Highly functional cellulose composite

ABSTRACT

A method for producing a cellulose composite containing cellulose and a polysaccharide, wherein a median size of colloidal cellulose composites contained in the cellulose composite as measured by a dynamic light scattering method is 0.85 μm or more, the method including treating a mixture containing cellulose, a polysaccharide and an aqueous medium together in a wet process, wherein a solid content is controlled to be 35 mass % or more, and temperature is set at 80° C. or less.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Divisional application of U.S. application Ser. No.14/237,688, filed Feb. 7, 2014, which is a National Stage of theInternational Application No. PCT/JP2012/070495, which claims priorityto Japanese Application No. 2011-176177, filed Aug. 11, 2011. Thedisclosure of application Ser. No. 14/237,688 and PCT/JP2012/070495 areexpressly incorporated by reference herein in their entireties.

TECHNICAL FIELD

The present invention relates to a highly functional cellulose compositeproviding a stable suspension state at a low viscosity for a long timeeven if it is added in a small amount to foods and drinks such ascocoas, coffees, teas and milks; industrial products such as abrasivesand paints; and medicinal products such as syrups. The present inventionalso relates to beverages such as cereal milk beverages, in which awater-insoluble substance is blended in a high concentration, havingexcellent suspension stability, texture and taste and flavor due toaddition of the cellulose composite.

BACKGROUND ART

A cellulose composite of cellulose and a polysaccharide has beenconventionally known to form cellulose colloid in an aqueous medium andshow satisfactory suspension stability and is widely used in the fieldsof e.g., foods, medicinal products, cosmetics, paints, ceramics, resins,catalysts and other industrial products. Particularly, a cellulosecomposite is used, e.g., as a stabilizer such as a suspensionstabilizer, an emulsification stabilizer and a thickening stabilizer, atexture imparting agent, a clouding agent, a whitening improvement, aflowability improvement, a polisher, a dietary fiber and an alternatematerial for a fat and oil. For example, in a beverage, e.g., calciumenriched milk, a cellulose composite is added for stabilizing suspensionof high-gravity water-insoluble components like milk calcium and calciumcarbonate.

Recently, in the field of canned or PET bottled tasty beverages such ascocoa, coffee and tea, products containing components such as cocoa, acoffee extract and a tea extract in high concentrations have beendeveloped for providing rich-taste to them. Generally, if the extract asmentioned above is added in a high concentration, the resultant beveragebecomes unstable and a water-insoluble component such as a protein islikely to precipitate. Thus, development of a cellulose composite withhigher suspension stability compared to conventional composites has beendesired.

Here, to improve the suspension-stability effect of a cellulosecomposite, various studies have been made.

Patent Literature 1 discloses a water-dispersible composite containingmicro cellulose and carboxymethylcellulose sodium.

Patent Literature 2 discloses a water dispersible composition containingmicro cellulose and a carboxymethylcellulose sodium of specific physicalproperties such as viscosity and substitution degree and a foodcomposition containing the water dispersible composition. The waterdispersible composition is described to show excellent suspensionstability and emulsion stability under an acidic environment.

Patent Literature 3 discloses a stabilizer containing water dispersiblecellulose, which contains fine fibrous cellulose that is stablysuspended in water and a polysaccharide. The stabilizer serves forfixing particles in an acidic or high salt concentration food and drinksuch as yogurt, fruit sauce and dressing, contributing to providingcommercial products having good appearance. Moreover, Patent Literature4 describes a fermented cellulose composite. Since the fermentedcellulose composite is excellent in dispersion stability and suspensionstability, it is used in various types of milk-containing beverages andstable acidic milk beverages can be produced.

Patent Literature 5 discloses a method of obtaining a cellulosecomposite from crystalline cellulose and sodium carboxymethylcelluloseas raw materials by grinding them in a solid content of 35 to 60 mass %,as a method of producing a dispersion stabilizer for solid particles.

CITATION LIST Patent Literature

Patent Literature 1: JP 40-12174 B

Patent Literature 2: JP 9-3243 A

Patent Literature 3: JP 2008-48604 A

Patent Literature 4: JP 2009-291081 A

Patent Literature 5: GB 1190112

SUMMARY OF INVENTION Technical Problem

However, conventional cellulose composites constituted of cellulose anda polysaccharide are likely to cause aggregation and separationparticularly in rich-taste beverages containing a component such ascocoa, a coffee extract and a tea extract in a high concentration andthe function as a stabilizer was not sufficiently achieved.

In the cellulose composites or water dispersible compositions describedin Patent Literatures 1 and 2, microcellulose itself has satisfactorydispersion stability. However, in rich-taste beverages containing acomponent in a high concentration, suspension stability thereof wasinsufficient. In addition to this problem, also in the case where awater-insoluble component such as a functional food material is added,suspension stability is insufficient and problems of sedimentation andaggregation occurred.

The fine fibrous cellulose or fermented cellulose described in PatentLiteratures 3 and 4 has an extremely thin and long shape and thus thestorage elastic modulus (G′) of a water dispersion becomes excessivelyhigh. As a result, it caused a problem: the texture (feeling in thethroat) of a food and drink containing the fermented cellulose becomesheavy. In addition, if the additive amount of the fermented cellulose isreduced to control texture, a problem of aggregation with a component ofa food and drink has occurred.

Patent Literature 5 does not describe temperature control in a step ofgrinding at all. Furthermore, the carboxymethylcellulose to be usedherein has an extremely high viscosity (2200 cps, 1 mass %) and thecarboxymethylcellulose is used alone. And the invention of PatentLiterature 5 differs from the present invention in which temperaturerange, and the amount of consumed power are accurately controlled in agrinding step. Accordingly, the cellulose composite (Comparative Example1 of the present application) obtained by the method of the Patentliterature 5 has a small median size measured by a dynamic lightscattering method and a small storage elastic modulus. As a result, whenbeverages were prepared by using the composite of the Patent literature5, beverages having satisfactory suspension stability, texture and tasteand flavor were not obtained.

An object of the present invention is to provide a cellulose compositehaving low viscosity and excellent dispersion stability and suspensionstability for a long time. Another object is to provide a cellulosecomposite having excellent suspension stability that has never ever beenattained in the prior art in food and drink containing a water-insolublecomponent such as a functional food material.

Hereinbelow, the “dispersion stability” and “suspension stability” usedin the specification of the present application is defined.

The “dispersion stability” refers to the dispersion stability of acellulose composite itself when the cellulose composite is dispersed inan aqueous medium. More specifically, the “dispersion stability” meansthat the aqueous medium gives homogenous appearance without causinge.g., separation, aggregation or sedimentation of cellulose particles.

The “suspension stability” means that when an aqueous medium containsthe components other than a cellulose composite, such as cocoa powder,calcium and a functional food material, these components are effectivelysuspended and stabilized by the addition of the cellulose composite.More specifically, the “suspension stability” means that the aqueousmedium gives homogenous appearance without causing e.g., separation,aggregation or sedimentation of not only cellulose but also othercomponent particles.

Solution to Problem

The present inventors produced a composite of cellulose and apolysaccharide so as to have a high composite degree. They found that ifthe cellulose composite, which contains a colloidal cellulose compositewith a predetermined median size in a predetermined amount is added to arich-taste beverage containing a component such as coffee, cocoa and atea extract in a high concentration, in a small amount, the resultantbeverage becomes low in viscosity and excellent in suspension stability.Based on the finding, they accomplished the present invention.

More specifically, the present inventors found that, in kneadingcellulose and a polysaccharide, if a semisolid-state kneading mixturehaving a high viscosity due to the presence of a solid substance in apredetermined concentration or more, is kneaded under application ofhigh kneading energy, the kneading energy easily transmits to thekneading mixture. As a result, they found that formation of a compositeof cellulose and a polysaccharide is facilitated and spread of apolysaccharide from cellulose in the colloidal cellulose compositecontained in the cellulose composite increases, in other words, themedian size measured by a dynamic light scattering method increases, andthat the resultant cellulose composite exhibits low viscosity and highsuspension stability for a long time.

To describe more specifically, the present invention is as follows:

(1) A cellulose composite containing cellulose and a polysaccharide,wherein a median size of colloidal cellulose composites contained in thecellulose composite as measured by a dynamic light scattering method is0.85 μm or more.

(2) The cellulose composite according to (1), wherein the cellulosecomposite has a storage elastic modulus (G′) of 0.50 Pa or more in awater dispersion of pH 6 to 7 which contains the cellulose composite inan amount of 1 mass %.

(3) The cellulose composite according to (1) or (2), wherein thecellulose composite contains a colloidal cellulose composite in anamount of 50 mass % or more.

(4) The cellulose composite according to any one of (1) to (3), whereinthe cellulose composite contains cellulose of 50 to 99 mass % and apolysaccharide of 1 to 50 mass %.

(5) The cellulose composite according to any one of (1) to (4), whereinthe polysaccharide is an anionic polysaccharide.

(6) The cellulose composite according to (5), wherein the anionicpolysaccharide is sodium carboxymethylcellulose.

(7) The cellulose composite according to any one of (1) to (6), whereinthe anionic polysaccharide contains xanthan gum in addition to sodiumcarboxymethylcellulose.

(8) A food and drink comprising the cellulose composite according to anyone of (1) to (7).

(9) A medicinal product comprising the cellulose composite according toany one of (1) to (7).

(10) An industrial product comprising the cellulose composite accordingto any one of (1) to (7).

(11) A food and drink, a medicinal product or an industrial productcomprising the cellulose composite according to any one of (1) to (7)and a water-insoluble component in an aqueous medium and having losstangent tan δ (loss elastic modulus G″/storage elastic modulus G′) of1.5 or more.(12) The food and drink according to (11), wherein the water-insolublecomponent is cocoa powder, cereal powder, fruit, or calcium, magnesium,zinc or a salt thereof.(13) The food and drink according to (11) or (12), wherein the food anddrink is an aqueous beverage, a milk beverage or a fruit beverage.(14) A method for producing the cellulose composite according to any oneof (1) to (7), comprising a step of treating a mixture containingcellulose, a polysaccharide and an aqueous medium together in a wetprocess, wherein a solid content is controlled to be 35 mass % or more,and temperature is set at 80° C. or less.(15) The method for producing the cellulose composite according to (14),wherein the polysaccharide is sodium carboxymethylcellulose and thesodium carboxymethylcellulose has a molecular-weight distribution, whichis obtained by gel permeation chromatography performed in a 0.05 Msodium hydroxide, having two (bimodal) peaks or more.(16) The method for producing the cellulose composite according to (14)or (15), wherein the sodium carboxymethylcellulose contains Component Ahaving a viscosity of 100 mPa·s or more and Component B having aviscosity of less than 100 mPa·s in a mass ratio of 5/95 to 95/5.(17) The method for producing the cellulose composite according to (15)or (16), wherein the sodium carboxymethylcellulose has a substitutiondegree of 1 or more.(18) A food and drink, a medicinal product, an industrial productcontaining a cellulose composite and a water-insoluble component in anaqueous medium and having a loss tangent, tan δ (loss elastic modulusG″/storage elastic modulus G′) of 1.5 or more.(19) A method for producing a cellulose composite, comprising a step oftreating a mixture containing a cellulose, a polysaccharide and anaqueous medium together in a wet process, wherein a solid content iscontrolled to be 35 mass % or more and temperature is set at 80° C. orless.(20) The method for producing the cellulose composite according to (19),wherein the polysaccharide is sodium carboxymethylcellulose and thesodium carboxymethylcellulose has a molecular-weight distribution, whichis obtained by gel permeation chromatography performed in a 0.05 Msodium hydroxide, having two (bimodal) peaks or more.

Advantageous Effects of Invention

The present invention can provide a cellulose composite having lowviscosity and excellent suspension stability. Owing to the addition ofthe cellulose composite of the present invention to a rich-tastebeverage containing a component such as coffee, cocoa and a tea extractin a high concentration, foods and drinks having low viscosity andexcellent suspension stability for a long time can be provided.Furthermore, when a water-insoluble component such as a functional foodmaterial is added to these foods and drinks, foods and drinks givinghomogeneous appearance and having excellent suspension stability can beprovided while suppressing e.g., separation, aggregation orsedimentation thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows AFM images (the left figure shows an image showing heightof a particle and the right figure shows an image formed by phasedifference) of cellulose composite D of Example 4.

FIG. 2 shows AFM images (the left figure shows an image showing heightof a particle and the right figure shows an image formed by phasedifference) of cellulose composite G of Comparative Example 1.

FIG. 3 shows a GPC chromatogram of sodium carboxymethylcellulose usedfor production in Examples 1, 3 to 5.

FIG. 4 shows a GPC chromatogram of sodium carboxymethylcellulose usedfor production in Example 2.

FIG. 5 shows a GPC chromatogram of sodium carboxymethylcellulose usedfor production in Example 8.

DESCRIPTION OF EMBODIMENTS

The present invention is more specifically described below.

The cellulose composite of the present invention refers to a cellulosecomposite containing cellulose and a polysaccharide, in which acolloidal cellulose composite contained in the cellulose composite has amedian size (measured by a dynamic light scattering method) of 0.85 μmor more. Also, the cellulose composite of the present invention refersto a cellulose composite having a storage elastic modulus (G′) of 0.50Pa or more in a water dispersion of pH 6 to 7 which contains thecellulose composite in an amount of 1 mass %. The formation of acomposite used in the present invention means that the surface ofcellulose is coated with a polysaccharide with the help of a chemicalbond such as a hydrogen bond.

<Cellulose>

In the present invention, the term “cellulose” refers to a naturallyderived water-insoluble fibrous substance containing cellulose. Examplesof a raw material thereof include wood, bamboo, straw, rice straw,cotton, ramie, bagasse, kenaf, beet, sea squirt and bacteria cellulose.These naturally occurring cellulose materials can be used singly or as amixture of two types or more, as a raw material.

<Average Polymerization Degree of Cellulose>

As the cellulose to be used in the present invention, crystallinecellulose having an average polymerization degree of 500 or less ispreferable. The average polymerization degree can be determined based onthe reduced specific viscosity method using a copper ethylene diaminesolution, which is defined in the crystalline cellulose identificationtest (3) of “the 14th edition of the Japanese Pharmacopoeia” (issued byHirokawa Shoten K.K.). The average polymerization degree is preferably500 or less because, in the step of forming a composite with apolysaccharide, a cellulose-based substance becomes subject to physicaltreatment such as stirring, pulverizing and grinding and formation of acomposite is easily accelerated. The average polymerization degree ismore preferably 300 or less and further preferably 250 or less. Thesmaller the average polymerization degree, the easier the control ofcomposite formation. Therefore, the lower limit is not particularlylimited; however, a preferable range is 10 or more.

<Hydrolysis of Cellulose>

As a method for controlling the average polymerization degree, e.g., ahydrolysis treatment is mentioned. Since depolymerization of amorphouscellulose within a cellulose fiber is accelerated by the hydrolysistreatment, the average polymerization degree decreases. At the sametime, since not only the amorphous cellulose mentioned above but alsoimpurities such as hemicellulose and lignin are removed by thehydrolysis treatment, the interior of the fiber becomes porous. Byvirtue of this, in a step of applying mechanical shearing force tocellulose and a polysaccharide, e.g., in a kneading step, the cellulosebecomes subject to mechanical treatment, thus it becomes subject topulverizing. As a result, the surface area of cellulose increases whichallows formation of a composite with a polysaccharide to be easilycontrolled.

Examples of the hydrolysis method include, but not particularly limitedto, acid hydrolysis, hydrothermal degradation, steam explosion andmicrowave decomposition. These methods may be used singly or incombination of two types or more. In the acid hydrolysis method, theaverage polymerization degree can be easily controlled by adding, e.g.,protonic acid, carboxylic acid, Lewis acid or heteropolyacid to acellulose substance dispersed in an aqueous medium, in an appropriateamount, and increasing temperature while stirring the obtained mixture.At this time, the reaction conditions such as temperature, pressure andtime vary depending upon the type of cellulose, cellulose concentration,type of acid and acid concentration but are appropriately controlled soas to attain a desired average polymerization degree. For example,conditions for treating cellulose by using an aqueous mineral acidsolution of 2 mass % or less at 100° C. or more under pressure for 10minutes or more are mentioned. In these conditions, a catalyst componentsuch as an acid permeates the interior of a cellulose fiber andaccelerates hydrolysis, with the result that the use amount of catalystcomponent decreases and the following purification is easily carriedout.

<Shape of Cellulose Particle (L/D)>

The cellulose contained in the cellulose composite of the presentinvention preferably has a micro particle shape. The particle shape ofthe cellulose is obtained by preparing a 1 mass % pure water suspensionof the cellulose composite of the present invention, dispersing thesuspension by a high-shear homogenizer (trade name “Excelautohomogenizer ED-7” manufactured by Nippon Seiki Co., Ltd., treatmentconditions: rotation number 15,000 rpm×5 minutes), diluting theresultant water dispersion with pure water to 0.1 to 0.5 mass %, castingthe diluted water dispersion onto mica, drying the resultant particlesin the air, and measuring thus dried resultant particles under ahigh-resolution scanning microscope (SEM) or an atomic force microscope(AFM) to obtain the particle images having the major axis (L) and theminor axis (D). The particle shape of the cellulose is represented by aratio L/D, which is calculated as an average (ratio) value of L/D of 100to 150 particles.

In view of suspension stability, the L/D value is preferably less than20, more preferably 15 or less, further preferably 10 or less,particularly preferably 5 or less, especially preferably less than 5 andmost preferably 4 or less.

<Polysaccharide>

The polysaccharide in the present invention refers to a compound inwhich saccharide units such as glucose, galactose, mannose, xylose,N-acetylglucosamine, gluconic acid, galacturonic acid and mannuronicacid are connected via a or β bond to constitute a main chain or a sidechain. Examples of the naturally-derived polysaccharides include resinderived polysaccharides such as almond gum, gum Arabic, arabinogalactan,elemi resin, gum karaya, gum ghatti, dammar resin, gum tragacanth andpeach gum; bean-derived polysaccharides such as linseed gum, cassia gum,locust bean gum, guar gum, an enzymatic decomposition product of guargum, psyllium seed gum, Artemisia sphaerocephala seed gum, Sesbania seedgum, Tamarindus seed gum, tara gum and Triacanthos gum; seaweed-derivedpolysaccharides such as alginic acid, carrageenan, a Fukuronori extractand furcellaran; polysaccharides derived from fruits, leaves andunderground stems such as an aloe vera extract, an okra extract, akrantz aloe extract, Tororoaoi and pectin; and polysaccharides derivedfrom microbial fermentation products such as Aeromonas gum, anAureobasidium cultured solution, Azotobacter vinelandii gum, welan Gum,erwinia mitsuensis gum, Enterobacter simanus gum, Enterobacter gum,curdlan, xanthan gum, gellan gum, sklero gum, dextran, Bacillus nattogum, pullulan, Macrophomopsis gum, ramzan gum and levan. Examples ofcellulose derived polysaccharides include cellulose, microfibrouscellulose, fermented cellulose, and cellulose derivatives such asmethylcellulose, ethylcellulose, hydroxyethylcellulose,hydroxypropylmethylcellulose, hydroxypropylcellulose,carboxymethylcellulose, carboxyethylcellulose and sodium salts andcalcium salts thereof. Examples of other polysaccharides include yeastcellwall, chitin, chitosan, glucosamine, oligoglucosamine, heparin andchondroitin sulfate.

These polysaccharides may be used alone or in combination of two ormore.

Of them, anionic or neutral polysaccharides are preferable for use inthe cellulose composite of the present invention since they are easilyformed into a composite with crystalline cellulose. An anionicpolysaccharide is further preferable since it is more easily formed intoa composite.

<Anionic Polysaccharide>

The polysaccharides, which release cations in water and serve as anionsper se are called anionic polysaccharide. An anionic polysaccharide ispreferably used in the present invention. This is because formation of acomposite with cellulose is further facilitated by using the anionicpolysaccharide.

As the anionic polysaccharide, the followings are preferable.

Examples thereof include psyllium seed gum, karaya gum, carrageenan,agar, furcellaran, heparin, chondroitin sulfate, alginic acid, sodiumalginate, calcium alginate, HM pectin, LM pectin, Azotobacter vinelandiigum, xanthan gum, gellan gum and a cellulose derivative such ascarboxymethylcellulose sodium, carboxymethylcellulose calcium, sodiumcarboxyethylcellulose and calcium carboxyethylcellulose. These anionicpolysaccharides may be used in combination with two or more types.

<Content of Colloidal Cellulose Composite in Cellulose Composite>

It is preferable that the cellulose composite of the present inventioncontains a colloidal cellulose composite in an amount of 50 mass % ormore. The content of the colloidal cellulose composite herein refers tothe mass percentage of a solid content (including cellulose and apolysaccharide, and if the cellulose composite of the present inventioncontains a water-soluble gum, the water-soluble gum is further included)remaining in the final supernatant, which is obtained by suspending thecellulose composite in pure water in a concentration of 0.5 mass %,dispersing the suspension by a high-shear homogenizer (trade name “Excelauto homogenizer ED-7”, manufactured by Nippon Seiki Co., Ltd.,treatment conditions: rotation number of 15,000 rpm×5 minutes),centrifuging it by a centrifuge (trade name “6800 type centrifuge”rotor-type RA-400, manufactured by KUBOTA Corporation, treatmentconditions: centrifugal force: 39200 m²/s) for 10 minutes, collectingthe supernatant and further centrifugally treating the supernatant at arate of 116000 m²/s for 45 minutes. If the content of a colloidalcellulose composite is 50 mass % or more, the suspension stabilityimproves. The content is further preferably 60 mass % or more and morepreferable 70 mass % or more. The higher the content of the colloidalcellulose composite, the higher the suspension stability. Thus, theupper limit of the content, which is not particularly limited, ispreferably 100 mass % or less.

<Spread of Polysaccharide of Composite*Median Size Measured by DynamicLight Scattering Method>

The cellulose composite of the present invention is characterized inthat spread of a polysaccharide radially extending from the surface of acellulose particle is larger than those of conventional composites. Thespread of a polysaccharide is represented by the median size of thecolloidal cellulose composites measured by a dynamic light scatteringmethod. In the cellulose composite of the present invention, the mediansize must be 0.85 μm or more.

The median size can be measured by a dynamic light scattering method inthe following manner. First, a cellulose composite is suspended in purewater in a concentration of 0.5 mass % and dispersed by a high-shearhomogenizer (trade name “Excel auto homogenizer ED-7”, manufactured byNippon Seiki Co., Ltd., treatment conditions: rotation number of 15,000rpm×5 minutes) and centrifugally separated by a centrifuge (trade name“6800 type centrifuge” rotor-type RA-400, manufactured by KUBOTACorporation, treatment conditions: centrifugal force of 39200 m²/s) for10 minutes. Then, the supernatant is collected and further centrifugallytreated at 116000 m²/s for 45 minutes. The resultant supernatant wascollected, placed in a 50-mL (volume) sample tube made of PP andultrasonically treated by an ultrasonic cleaner (an ultrasonic cleaner,trade name: AUC-1L type manufactured by AS ONE Corporation) for 10minutes. Thereafter, a particle size distribution (frequencydistribution of scattering intensity versus particle size value) ismeasured by a zeta potential-particle size measurement system (tradename “ELSZ-2” (batch cell), manufactured by Otsuka Electronic Co.,Ltd.). The median size herein refers to a particle size value (μm)corresponding to a cumulative 50% scattering intensity in the frequencydistribution. The larger the median size, the more excellent thesuspension stability of a cellulose composite. Thus, the median size ispreferably 0.90 μm or more, more preferably 1.0 μm or more, furtherpreferably 1.1 μM or more and particularly preferably 1.2 μm or more.The upper limit, which is not particularly limited, is preferably 5.0 μmor less, more preferably 3.0 μm or less, further preferably 2.0 μm orless and particularly preferably 1.5 μm or less.

<Sodium Carboxymethylcellulose>

Of the anionic polysaccharides mentioned above, sodiumcarboxymethylcellulose (hereinafter referred to as CMC-Na) isparticularly preferable since it can easily form a composite withcellulose. The CMC-Na herein refers to a chemical compound obtained bysubstituting a hydroxy group of cellulose with monochloroacetic acid andhaving a linear chemical structure of D-glucose units linked via a β-1,4bond. CMC-Na is obtained by dissolving pulp (cellulose) in a sodiumhydroxide solution and substituting with monochloroacetic acid (or asodium salt thereof).

Particularly, CMC-Na, which is prepared such that its substitutiondegree and viscosity fall within predetermined ranges, is preferablyused in view of formation of a composite.

As the viscosity of CMC-Na, 500 mPa·s or less, which is a viscosity of 1mass % pure aqueous solution of CMC-Na, is preferable. The viscosityherein is measured in the following manner. First, CMC-Na powder isdispersed in pure water so as to obtain a concentration of 1 mass % byuse of a high-shear homogenizer (trade name “Excel auto homogenizerED-7”, manufactured by Nippon Seiki Co., Ltd., treatment conditions:rotation number of 15,000 rpm×5 minutes) to prepare an aqueous solution.Three hours (stored at 25° C.) after the dispersion, the resultantaqueous solution is set in a B-type viscometer (rotor revolving speed:60 rpm), allowed to stand still for 60 seconds and rotated for 30seconds, and then, the viscosity is measured. Note that the rotor can beappropriately changed depending upon the viscosity. The lower theviscosity of CMC-Na, the more easily a composite with cellulose and apolysaccharide is formed. Because of this, the viscosity is morepreferably 200 mPa·s or less and further preferably 100 mPa·s or less.The lower limit, which is not particularly specified, is preferably 1mPa·s or more.

<Combination of “CMC-Na”>

As the CMC-Na to be used in the cellulose composite of the presentinvention, preferably two types of CMC-Na different in viscosity areused in combination. Specifically, the combination of CMC-Na preferablycontains component A having a viscosity (measured in a 2 mass % aqueoussolution thereof at 25° C.) of 100 mPa·s or more and component B havinga viscosity (measured in a 2 mass % aqueous solution thereof at 25° C.)of less than 100 mPa·s in a blending ratio, i.e. Component A/ComponentB=5/95 to 95/5 (mass ratio).

The viscosity herein is measured in the following manner. First, CMC-Napowder is dispersed in a pure water so as to obtain a concentration of 2mass % by use of a high-shear homogenizer (trade name “Excel autohomogenizer ED-7”, manufactured by Nippon Seiki Co., Ltd., treatmentconditions: rotation number of 15,000 rpm×5 minutes) to prepare anaqueous solution. Then, three hours (stored at 25° C.) after thedispersion, the resultant aqueous solution is set in B-type viscometer(rotor revolving speed: 60 rpm), allowed to stand still for 60 secondsand rotated for 30 seconds. In this manner, the viscosity is measured.Note that the rotor can be appropriately changed depending upon theviscosity.

Herein, Component A (high-viscosity CMC-Na), when it is combined withcellulose into a composite, radially spreads from the surface of thecellulose if the composite is dispersed in water and tangled with CMC-Naof the adjacent composite. In this manner, a rigid network structure ofthe cellulose composites is made, with the result that the storageelastic modulus (G′) of a water dispersion increases. The viscosity ofComponent A is preferably set within a proper range. This is because thespread of CMC-Na from the cellulose surface increases. The viscosity ofComponent A is more preferably 200 mPa·s or more, further preferably 300mPa·s or more and particularly preferably 500 mPa·s or more. The upperlimit is preferably 10000 mPa·s or less, more preferably 5000 mPa·s orless, further preferably 2000 mPa·s or less and particularly preferably1000 mPa·s or less.

Component B (low-viscosity CMC-Na) serves to stiffen the mixture ofcellulose and a polysaccharide to be kneaded. As a result, power can beeasily applied to the kneading mixture, facilitating formation of acomposite effectively in a predetermined time. The viscosity ofComponent B is correlated with the above-mentioned composite-formationfacilitating effect. The viscosity of Component B is more preferably 90mPa·s or less, further preferably 70 mPa·s or less, particularlypreferably 50 mPa·s or less and most preferably 30 mPa·s or less. Thelower limit is preferably 1 mPa·s or more, more preferably 5 mPa·s ormore, further preferably 10 mPa·s or more and particularly preferably 20mPa·s or more.

Depending upon the blending ratio of Component A and Component B,easiness in forming a cellulose composite and function of the resultantcellulose composite can be adjusted. As the blending ratio (mass ratio),Component A/Component B=10/90 to 90/10 is more preferable, 20/80 to80/20 is further preferable, 30/70 to 70/30 is particularly preferableand 40/60 to 60/40 is most preferable.

<Molecular-Weight Distribution of CMC-Na>

The CMC-Na to be used in the present invention preferably has achromatogram having two (bimodal) peaks or more, which is obtained inmeasuring the molecular weight of CMC-Na by gel permeationchromatography (GPC).

Two (bimodal) peaks or more means that a GPC chromatogram has a curvehaving two or more discrete peaks (two peak tops or more). The curvehaving such a shape means that the molecular-weight distribution is notmonodispersed. Since a plurality of components are mixed, the componentsmutually compensate, with the result that spread of CMC-Na from thesurface of cellulose increases to obtain a cellulose composite havinghigh G′.

The gel permeation chromatography herein is performed by use of a highperformance liquid chromatographic (HPLC) apparatus (trade name TypeLC-20A, manufactured by Shimadzu Corporation), to which a single column(trade name TSK-GEL G5000PW type (7.8 mm×30 cm), manufactured by TosohCorporation) and two columns (trade name TSK-GEL G3000 PWXL type (7.8mm×30 cm)) are connected in line. Measurement is performed by supplyingan aqueous 0.05 mol/L sodium hydroxide solution as a mobile phase, at aflow rate of 1 mL/minute and setting a column temperature at 30° C.Detection is made by an RI detector or a UV detector (wavelength: 210nm) to obtain a chromatogram. In the resultant chromatogram, two(bimodal) peaks or more are detected.

CMC-Na to be used herein is completely dissolved in the same solution asused in the above mobile phase and then put in use. The concentration ofthe CMC-Na solution is appropriately adjusted within the range of 0.01to 1.0 mass %. Measurement is performed by injecting the CMC-Na solutionin a dose of 5 to 10 μL/time.

Owing to the use of CMC-Na, whose molecular weight distribution is notsingle dispersion but has at least two (bimodal) peaks, the surfacecharge of the cellulose composite becomes high and CMC-Na spreads morewidely. For this reason, CMC-Na having a molecular weight distributionof two (bimodal) peaks or more is preferably used.

<Substitution Degree of CMC-Na>

CMC-Na to be used in the cellulose composite of the present inventionpreferably has a high substitution degree. This is because the higherthe substitution degree of CMC-Na, the more easily CMC-Na is combinedwith cellulose into a composite, with the result that the cellulosecomposite exhibits a higher storage elastic modulus and high suspensionstability even in an aqueous solution having a high salt concentration(for example, an aqueous 10 mass % sodium chloride solution).Furthermore, owing to use of CMC-Na having a high substitution degree,excessive aggregation with a protein such as a milk component rarelyoccurs. The substitution degree refers to a ratio of a carboxymethylgroup binding to a hydroxy group of cellulose via an ether bond.Specifically, the substitution degree is preferably 0.5 or more, morepreferably 1.0 or more, further preferably 1.2 or more and particularlypreferably 1.3 or more. The upper limit is preferably 3 or less, morepreferably 2 or less and further preferably 1.5 or less.

The substitution degree herein is measured in the following manner. Asample (anhydride) (0.5 g) is accurately weighed, wrapped with a filterand baked in a magnetic crucible into ash. After cooling, this istransferred to a 500 mL beaker. To the beaker, water (about 250 mL) and0.05 M sulfuric acid (35 mL) are added. The mixture is boiled for 30minutes. The resultant mixture is cooled and a phenolphthalein indicatoris added. Excessive acid is neutralized by back titration with 0.1 Mpotassium hydroxide. The substitution degree is calculated by thefollowing expressions.A=((af−bf1)/sample anhydride (g))−alkali level (or +acid level)Substitution degree=(162×A)/(10000−80A)whereA: Amount of 0.05 M sulfuric acid (mL) consumed by alkali per sample (1g)a: Use amount of 0.05 M sulfuric acid (mL)f: Titer of 0.05 M sulfuric acidb: Titer (mL) of 0.1 M potassium hydroxidef1: Titer of 0.1 M potassium hydroxide162: Molecular weight of glucose80: Molecular weight of CH₂COONa—H

Method of Measuring Alkali Level (or Acid Level):

A sample (anhydride) (1 g) is accurately weighed in a 300 mL-flask. Tothis flask, water (about 200 mL) is added to dissolve the sample. Tothis, 0.05 M sulfuric acid (5 mL) is added and the mixture is boiled for10 minutes and cooled. To this resultant mixture, a phenolphthaleinindicator is added and titrated with 0.1 M potassium hydroxide (S mL).At the same time, a blank test is performed (B mL). The alkali level iscalculated in accordance with the following expression.Alkali level=((B−S)×f)/sample anhydride (g)where f: Titer of 0.1 M potassium hydroxide. If a value of {(B−S)×f} isa negative value (−), the alkali level is regarded as an acid level.<Blending Ratio of Cellulose and Polysaccharide>

The cellulose composite of the present invention preferably containscellulose in an amount of 50 to 99 mass % and a polysaccharide in anamount of 1 to 50 mass %. In forming a composite, the surface of acellulose particle is coated with a polysaccharide via a chemical bondsuch as a hydrogen bond. By virtue of this, when such a cellulosecomposite is dispersed in a neutral aqueous solution, the suspensionstability of the cellulose composite improves. Furthermore, formation ofa composition is facilitated by using cellulose and a polysaccharidesatisfying the aforementioned contents and the suspension stability ofthe neutral water dispersion improve to easily attain an effect ofpreventing sedimentation of a water-insoluble component such as afunctional food material. The cellulose composite of the presentinvention more preferably contains cellulose in an amount of 70 to 99mass % and a polysaccharide in an amount of 1 to 30 mass %, furtherpreferably contains cellulose in an amount of 80 to 99 mass % and apolysaccharide in an amount of 1 to 20 mass % and particularlypreferably contains cellulose in an amount of 85 to 99 mass % and apolysaccharide in an amount of 1 to 15 mass %.

<Particle Size of a Cellulose Core in Cellulose Composite*Median Size byLaser Diffraction/Scattering Method>

The median size of the colloidal cellulose composites in the cellulosecomposite of the present invention, as measured by a laserdiffraction/scattering method, is preferably 1.0 μm or less. The mediansize measured by this method represents the particle size of a cellulosecore present at the center of the cellulose composite, different fromthat measured by the dynamic light scattering method as mentioned above.The median size can be measured by the laser diffraction/scatteringmethod in the following manner.

First, a cellulose composite is suspended in pure water in aconcentration of 0.5 mass %, dispersed by a high-shear homogenizer(trade name “Excel auto homogenizer ED-7”, manufactured by Nippon SeikiCo., Ltd., treatment conditions: rotation number of 15,000 rpm×5minutes), centrifugally separated by a centrifuge (trade name “6800 typecentrifuge” rotor-type RA-400, manufactured by KUBOTA Corporation,treatment conditions: centrifugal force of 39200 m²/s) for 10 minutes.The supernatant is collected and further centrifugally treated at a rateof 116000 m²/s for 45 minutes and the resultant supernatant iscollected. The supernatant is measured by a laser diffraction/scatteringparticle size distribution meter (trade name “LA-910” manufactured byHoriba, Ltd. ultrasonic treatment: 1 minute, refractive index 1.20). Inthe obtained volume frequency particle size distribution, the cumulative50% particle size (a volume average particle size) is the particle sizeof a cellulose core in cellulose composite. The smaller the value ofthis particle size, the more preferable because the suspension stabilityof a cellulose composite becomes excellent. The value is more preferably0.7 μm or less, further preferably 0.5 μm or less, particularlypreferably 0.3 μm or less and most preferably 0.2 μm or less.

<Size of Coarse Particles in Cellulose Composite*the Median Size byLaser Diffraction/Scattering Method>

The cellulose composite of the present invention is characterized inthat the median size of coarse particles contained therein is small. Thesize of the coarse particles can be measured in the following manner.First, a cellulose composite is suspended in pure water in aconcentration of 0.5 mass % and dispersed by a high-shear homogenizer(trade name “Excel auto homogenizer ED-7”, manufactured by Nippon SeikiCo., Ltd., treatment conditions: rotation number of 15,000 rpm×5minutes). The dispersion is directly (without subjecting to centrifugalseparation) subjected to a laser diffraction/scattering particle sizedistribution meter (trade name “LA-910” manufactured by Horiba, Ltd.ultrasonic treatment: 1 minute, refractive index 1.20). In the obtainedvolume frequency particle size distribution, the cumulative 50% particlesize (volume average particle size) is the size of coarse particles incellulose composite. The median size is preferably 20 μm or less,because the suspension stability of a cellulose composite is more easilyimproved. Furthermore, if the cellulose composite is contained in food,food having smooth texture without grainy feeling on tongue can beprovided. The median size is more preferably 15 μm or less, particularlypreferably 10 μm or less, and further preferably 8 μm or less. The lowerlimit, which is not particularly limited, is preferably 0.1 μM or more.

<Storage Elastic Modulus of Cellulose Composite>

Next, the storage elastic modulus (G′) of the cellulose composite of thepresent invention is described.

The cellulose composite of the present invention has a storage elasticmodulus (G′) of 0.50 Pa or more, which is obtained as the storageelastic modulus in a water dispersion of pH 6 to 7 containing 1 mass %of the cellulose composite. The storage elastic modulus representsrheological elasticity of a water dispersion, and represents degree ofcomposite formation between cellulose and a polysaccharide or degree ofcomposite formation between cellulose and a polysaccharide and anotherwater soluble gum. A higher storage elastic modulus means that thecomposite formation between cellulose and a polysaccharide or thecomposite formation between cellulose and a polysaccharide and anotherwater soluble gum is accelerated to form a rigid network structure of acellulose composite in a water dispersion. The more rigid the networkstructure becomes, the more excellent the suspension stability acellulose composite has.

In the present invention, the storage elastic modulus is defined as avalue obtained by measuring dynamic viscoelasticity of a waterdispersion (pH 6 to 7) in which a cellulose composite is dispersed inpure water. When distortion is given to the water dispersion, theelastic component which keeps stress stored within a cellulose compositenetwork structure, is expressed as a storage elastic modulus.

A method for measuring storage elastic modulus is as follows: first, acellulose composite is dispersed in pure water by use of a high-shearhomogenizer (trade name “Excel autohomogenizer ED-7” manufactured byNippon Seiki Co., Ltd., treatment conditions: rotation number 15,000rpm×5 minutes) to prepare a 1.0 mass % pure water dispersion. Theresultant water dispersion is allowed to stand still at room temperaturefor 3 days. The distortion-dependent stress of the water dispersion ismeasured by a viscoelasticity measurement apparatus (ARES100FRTN1 type,manufactured by Rheometric Scientific, Inc., geometry: Double WallCouette type, sweeping is performed at a constant temperature at 25.0°C. and an angular velocity of 20 rad/second within a distortion range of1 to 794%; a water dispersion is slowly supplied by use of a dropper soas not to destroy a microstructure and allowed to stand still for 5minutes and then measurement is initiated by Dynamic Strain mode). Thestorage elastic modulus of the present invention refers to a valuecorresponding to a distortion of 20% on the distortion-stress curveobtained by the aforementioned measurement. The larger the storageelastic modulus value, the more elastic the structure of the waterdispersion formed of the cellulose composite, and this represents thatcellulose and a polysaccharide, or cellulose and a polysaccharide andanother water soluble gum are highly combined.

The storage elastic modulus of a cellulose composite is preferably 0.75Pa or more, more preferably 1.0 Pa or more, further preferably 1.3 Pa ormore, particularly preferably 1.6 Pa or more and most preferably 1.8 Paor more.

The upper limit thereof is not particularly determined; however, in viewof easy-to-take as a beverage, the upper limit is 6.0 Pa or less. Theupper limit of 6.0 Pa or less is preferable because a beveragecontaining a cellulose composite in the additive amount (which variesdepending upon the beverage, for example, 0.1 to 1.0 mass %, in tastybeverages such as coffee, cocoa and tea or beverages such as Ca-enrichedmilk) at which suspension stability is sufficiently obtained, giveslight feeling in the throat. Furthermore, even in the case where theadditive amount of cellulose composite is lowered to control texture(for example, 0.5 mass % or less), aggregation or the like with a waterinsoluble component other than cellulose rarely occurs.

<Structure of Cellulose Composite>

The cellulose composite of the present invention is characterized in thespreading of a polysaccharide radially extending from the surface ofcellulose is large, compared to the conventional products. The largerthe spreading of a polysaccharide extending from the surface ofcellulose, the easier to get tangled with adjacent polysaccharide of thecellulose composite. As a result, cellulose composites get tangleddensely with each other to obtain a rigid network structure. In thismanner, storage elastic modulus (G′) improves, and suspension stabilityincrease. The spreading of a polysaccharide can be measured by thefollowing method.

First, a cellulose composite is dispersed by a high-shear homogenizer(trade name “Excel autohomogenizer ED-7” manufactured by Nippon SeikiCo., Ltd., treatment conditions: rotation number 15,000 rpm×5 minutes,total amount 300 g) in pure water to prepare a 1.0 mass % pure waterdispersion. The resultant water dispersion is allowed to stand still atroom temperature for 3 days or more. Thereafter, the water dispersion isdiluted 20 folds with pure water to prepare a sample solution. From thewater dispersion, an aliquot (5 μl) is slowly suctioned by use of adropper so as not to destroy a microstructure of the water dispersionand allowed to slowly fall in drops on cleaved mica (1 cm×1 cm). Afterextra moisture content is blown out by an air duster, the sampledeposited on the mica is observed by AFM (scanning probe microscopeSPM-9700, manufactured by Shimadzu Corporation, phase mode, as a probe,OMCL-AC240TS manufactured by Olympus Corporation is used). In the imageunder observation, a cellulose particle is seen as a rod-form particlehaving a height of 2 nm or more and a polysaccharide having a height ofless than 2 nm radially extended from the cellulose particleperipherally can be observed (FIG. 1). In the present invention, spreadof a polysaccharide radially extending from a cellulose particle isexpressed by the median size of the colloidal cellulose compositesmeasured by a dynamic light scattering method.

A polysaccharide preferably has a high composite degree, because thespread of the polysaccharide becomes larger. Furthermore, if CMC-Nahaving a predetermined substitution degree and viscosity is used as apolysaccharide, the spread becomes larger. If two types of CMC-Na havingpredetermined viscosity values are used in combination, the spreadbecomes further larger.

<Viscosity of Water Dispersion of Cellulose Composite>

The cellulose composite of the present invention is characterized inthat since spread of CMC-Na from a cellulose particle is large asmentioned above, the cellulose particle easily gets tangled with theadjacent particle in a water dispersion. Because of this, the cellulosecomposite of the present invention has higher viscosity thanconventional products. In addition, if the cellulose composite is addedto a food and drink, it can provide satisfactory textures such asrich-taste and smooth sensation going down the throat (easy-to-take).The viscosity herein can be measured in the following manner.

First, a cellulose composite is dispersed in pure water by use of ahigh-shear homogenizer (trade name “Excel auto homogenizer ED-7”,manufactured by Nippon Seiki Co., Ltd., treatment conditions: rotationnumber of 15,000 rpm×5 minutes) to prepare a dispersion in pure waterhaving a concentration of 1.0 mass %. Three hours (stored at 25° C.)after the dispersion, the water dispersion is set in B-type viscometer(rotor revolving speed: 60 rpm), allowed to stand still for 30 secondsand rotated for 30 seconds, and then, the viscosity is measured. Notethat the rotor can be appropriately changed depending upon theviscosity. The rotors used herein are as follows: 1 to 20 mPa·s: BLtype, 21 to 100 mPa·s: No. 1, 101 to 300 mPa·s: No. 2, 301 mPa·s ormore: No. 3.

A preferable range of viscosity of a water dispersion of cellulosecomposite is 100 mPa·s or more. The range is more preferably 150 mPa·sor more, further preferably 200 mPa·s or more, further more preferably250 mPa·s or more, particularly preferably 300 mPa·s or more, and mostpreferably 350 mPa·s or more. The upper limit, which is closelyconnected to easy-to-take, is preferably 1000 mPa·s or less, morepreferably 700 mPa·s or less, further preferably 600 mPa·s or less andparticularly preferably 500 mPa·s or less.

<Water Soluble Gum>

It is preferable that the cellulose composite of the present inventionfurther contains a water soluble gum other than a polysaccharide. As thewater soluble gum, a gum highly swellable and easily forming a compositewith cellulose is preferable.

Examples thereof include locust bean gum, guar gum, tamarind seed gum,karaya gum, chitosan, gum arabic, agar, carrageenan, alginic acid,alginate such as sodium alginate, calcium alginate, pectins such as HMpectin, LM pectin, Azotobacter vinelandii gum, xanthan gum, curdlan,pullulan, dextran, gellan gum, gelatin, cellulose derivatives such ascarboxymethylcellulose calcium, methylcellulose, hydroxypropylcelluloseand hydroxyethylcellulose. They may be used in combination of two typesor more.

Among the water-soluble gums mentioned above, in view of formation of acomposite with cellulose, xanthan gum, karaya gum, gellan gum, pectinand alginate are preferable.

<Mass Ratio of Polysaccharide and Water Soluble Gum>

The mass ratio of a polysaccharide and a water soluble gum as mentionedabove is preferably 30/70 to 99/1. In the cellulose composite of thepresent invention, if the ratio of a polysaccharide and a water solublegum as mentioned above falls within the above range, the cellulosecomposite of the present invention exhibits suspension stability in awater dispersion containing the cellulose composite of the presentinvention within a broad pH range from weak alkaline (pH8) to acidic(pH3). The content ratio of a polysaccharide and a water soluble gum ismore preferably 40/60 to 90/10 and further preferably 40/60 to 80/20.

<Hydrophilic Substance>

To improve dispersibility to water, a hydrophilic substance other than apolysaccharide and a water soluble gum may be further added to thecellulose composite of the present invention. The hydrophilic substancerefers to an organic substance highly soluble in cool water and rarelyincreasing viscosity. Examples of suitable organic substance includehydrophilic polysaccharides such as a starch hydrolysate, dextrins, anindigestible dextrin, and a polydextrose; oligosaccharides such asfructo-oligosaccharide, galactooligosaccharide, maltooligosaccharide,isomaltooligosaccharide, lactose, maltose, sucrose and α-, β- andγ-cyclodextrin; monosaccharides such as glucose, fructose and sorbose;and sugar alcohols such as maltitol, sorbitol and erythritol. Thesehydrophilic substances may be used in combination with two types ormore. Of the aforementioned organic substances, a hydrophilicpolysaccharide, such as a starch hydrolysate, dextrins, an indigestibledextrin and a polydextrose, is preferable in view of dispersibility.

Other components may be freely added to the extent that they do notdisturb dispersibility and stability of a composition in water.

<Method for Producing Cellulose Composite>

Next, a method for producing the cellulose composite of the presentinvention is described.

The cellulose composite of the present invention containing a colloidalcellulose composite having a predetermined median size in apredetermined amount is obtained by applying mechanical shearing forceto cellulose and a polysaccharide in a kneading step to make celluloseinto small pieces, and combining the polysaccharide to the surface ofthe cellulose pieces to make a composite. Furthermore, a water solublegum other than a polysaccharide, hydrophilic substance and otheradditives may be added. The composite obtained through the treatment inthe aforementioned process is, if necessary, dried. The cellulosecomposite of the present invention subjected to the aforementionedmechanical shearing may be in any state such as undried and dried.

To apply mechanical shearing force, a kneading method using a kneadingmachine, etc. can be used. Examples of the kneading machine include akneader, an extruder, a planetary mixer and a grinder (Raikai mixer).They may be used in a continuous system or a butch system. As thekneading temperature, a natural process temperature may be used;however, if heat is generated from a reaction for forming a compositeand friction, etc. during a kneading process, kneading may be performedwhile removing the generated heat. These machines may be used singly orin combination of two types or more. These machines may be appropriatelyselected depending upon the requirement of viscosity, etc., in varioususes.

Furthermore, the lower the kneading temperature, the more suppressed thedeterioration of a polysaccharide, with the result that the storageelastic modulus of a cellulose composite (G′) increases and thuspreferable. The kneading temperature is preferably 80° C. or less, morepreferably 70° C. or less, further preferably 60° C. or less, morefurther preferably 50° C. or less, particularly preferably 30° C. orless and most preferably 20° C. or less. To maintain the above-mentionedkneading temperature under high energy, it is free to use a coolingmeans such as jacket cooling and heat radiation.

The solid content during a kneading process is preferably 35 mass % ormore. If the mixture in a semisolid state having high viscosity iskneaded, the kneaded mixture does not become watery and thus kneadingenergy as described below can be easily transferred to the kneadedmixture to facilitate formation of a composite and thus preferable. Thesolid content during a kneading process is more preferably 40 mass % ormore, further preferably 50 mass % or more and particularly preferably55° C. mass % or more. The upper limit is not particularly limited;however, in consideration of avoiding dry state (low-moisture content)of a kneaded mixture and obtaining a sufficient kneading effect andhomogeneous kneading state, a practical range is preferably 90 mass % orless, more preferably 70 mass % or less and further preferably 60 mass %or less. Furthermore, to adjust the solid content so as to fall withinthe above range, a necessary amount of water may be added before akneading step or during the kneading step or both timings.

Hereinbelow, kneading energy is described. The kneading energy isdefined by electric energy per unit mass (Wh/kg) of a kneaded mixture.The kneading energy is preferably 50 Wh/kg or more. If the kneadingenergy is 50 Wh/kg or more, the grinding power given to the kneadedmixture is high and formation of a composite between cellulose and apolysaccharide or between cellulose, a polysaccharide and another watersoluble gum, etc. is accelerated, with the result that, the suspensionstability of a neutral cellulose composite is improved. The kneadingenergy is more preferably 80 Wh/kg or more, further preferably 100 Wh/kgor more and particularly preferably 200 Wh/kg or more, further morepreferably 300 Wh/kg or more and most preferably 400 Wh/kg or more.

It is considered that the higher the kneading energy becomes, the morethe formation of a composite is facilitated. However, if the kneadingenergy is excessively high, excessively large equipment is industriallyrequired. Since excessively large load is applied to the equipment, theupper limit of kneading energy is preferably set to be 1000 Wh/kg.

The degree of formation of a composite is conceived to be the ratio ofhydrogen bonds between cellulose and the other component. As theformation of a composite proceeds, the ratio of hydrogen bonds increasesand the effect of the present invention improves. Furthermore, ifformation of a composite proceeds, the median size of colloidalcellulose composites contained in a cellulose composite increases.

In obtaining the cellulose composite of the present invention, when thekneaded mixture obtained in the kneading step mentioned above is dried,a known drying method such as a shelf-stage drying, mist drying, beltdrying, fluid-bed drying, lyophilization and a microwave drying can beused. When a kneaded mixture is subjected to a drying step, it ispreferable that a kneaded mixture is subjected to a drying step withoutadding water while maintaining the solid content concentration from thekneading step.

The moisture content of a cellulose composite after drying is preferably1 to 20 mass %. If the moisture content is 20% or less, problems ofe.g., stickiness and decay, and a problem in transportation and carriagecost rarely occur. The moisture content is more preferably 15% or lessand particularly preferably 10% or less. Furthermore, if the moisturecontent is 1% or more, dispersibility is not deteriorated due tooverdrying. The moisture content is more preferably 1.5% or more.

For marketing a cellulose composite, powder form is easily handled.Therefore, the dried cellulose composite is preferably pulverized intopowder. However, when spray drying is employed as a drying method,drying and powderization can be simultaneously carried out. In thiscase, pulverization is not necessary. For pulverizing the driedcellulose composite, a known means such as a cutter mill, a hammer mill,a pin mill and a jet mill can be used. Pulverization is performed to theextent that the pulverized cellulose composite can completely passthrough a sieve having an opening of 1 mm, more preferably a sievehaving an opening of 425 μm and preferably performed so as to obtain anaverage particle size (weight average particle size) of 10 to 250 μm.These dried powders form a secondary aggregate by aggregatingmicroparticles of a cellulose composite. When the secondary aggregate isstirred in water, it collapses into cellulose composite microparticlesas mentioned above. The apparent weight average particle size of thesecondary aggregates refers to a cumulative weight 50% particle size ina particle size distribution obtained by sieving a sample (10 g) bymeans of a ro-tap system sieve shaker (Sieve shaker A type manufacturedby Taira Kosakusho) and a JIS standard sieve (Z8801-1987) for 10minutes.

When the dried cellulose composite is stirred in water, the composite iseasily dispersed to form a stable colloidal dispersion having cellulosehomogeneously dispersed and having smooth texture without grainyfeeling. Particularly, the cellulose composite forms, in a neutralstate, a stable colloidal dispersion without causing aggregation andseparation of cellulose and thus exerts an excellent function as astabilizer, etc.

<High-Level Composite Formation at Low Temperature>

As described above, the cellulose composite of the present invention ispreferably obtained by blending, as a polysaccharide, two types ofCMC-Na different in viscosity in a predetermined ratio.

On the other hand, in the present invention, even if a single CMC-Nahaving a low viscosity is used in place of two types of CMC-Na differentin viscosity, a cellulose composite having excellent suspensionstability can be obtained by further reducing the kneading temperaturein the production method mentioned above.

The viscosity of the CMC-Na to be used herein is preferably 100 mPa·s orless, more preferably 90 mPa·s or less, further preferably 70 mPa·s orless, particularly preferably 50 mPa·s or less and most preferably 30mPa·s or less. The lower limit is preferably 1 mPa·s or more, morepreferably 5 mPa·s or more, further preferably 10 mPa·s or more andparticularly preferably 20 mPa·s or more.

The viscosity herein is measured in the following manner. First, CMC-Napowder is dispersed in pure water so as to obtain a concentration of 2mass % by use of a high-shear homogenizer (trade name “Excel autohomogenizer ED-7”, manufactured by Nippon Seiki Co., Ltd., treatmentconditions: rotation number of 15,000 rpm×5 minutes) to prepare anaqueous solution. Then, three hours (stored at 25° C.) after thedispersion, the resultant aqueous solution is set in B-type viscometer(rotor revolving speed: 60 rpm), allowed to stand still for 60 secondsand rotated for 30 seconds, and then, the viscosity was measured. Notethat, the rotor can be appropriately changed depending upon theviscosity.

Furthermore, the lower the kneading temperature, the more preferablesince the storage elastic modulus (G′) of a composite increases. Thekneading temperature is preferably 0 to 50° C., more preferably 40° C.or less, particularly preferably 30° C. or less, further preferably 20°C. or less and most preferably 10° C. or less. When kneading isperformed at 20° C. or less, the operation until CMC-Na is swollen withwater (from initiation of kneading and the amount of electricity reaches30 Wh/kg) can be made at room temperature or more.

<Uses>

The cellulose composite of the present invention can be used in varioustypes of food products. Examples of uses include various beveragesincluding tasty beverages such as coffee, tea, powdered green tea,cocoa, sweet red-bean soup and juice, milk beverages such as raw milk,processed milk, lactobacillus beverage and soy milk, nutrition enrichedbeverages such as calcium enriched beverage and dietary fiber containingbeverages; edible ices such as ice cream, ice milk, soft cream, milkshake and sherbet; milk products such as butter, cheese, yogurt, coffeewhitener, whipping cream, custard cream and pudding; processed fat andoil food products such as mayonnaise, margarine, spread and shortening;seasonings such as soup, stew, sauce, baste and dressing; spice pastesrepresented by mustard paste; fillings represented by jam and flowerpaste; gel paste foods such as bean paste and jelly; cereal foodsincluding bread, noodle, pasta, pizza and premix; Japanese and westernconfectioneries such as candy, cookie, biscuit, pancake, chocolate andrice cake; fish paste products represented by fish sausage and Hanppen;livestock products represented by ham, sausage and hamburger steak;prepared foods such as cream croquette, filling for Chinese food, gratinand dumpling; food delicacies such as salted fish guts and pickles withlees; pet foods; and tubal fluid foods.

In these uses, the cellulose composite of the present invention servesas a base reducing calory, such as a suspension stabilizer, anemulsification stabilizer, a thickening stabilizer, a foam stabilizer, acloudy agent, a texture-adding agent, a fluidity improver, a shaperetaining agent, a syneresis inhibitor, a dough modifier, a powder base,a dietary fiber base and oil and fat alternative. Furthermore, even ifthe above foods are processed such that they are prepared by differentcooking patterns in use such as retort food, powdered food, frozen food,food for microwave meal, the effect of the present invention is exerted.Particularly, the cellulose composite of the present invention functionseven in a heating environment and a high concentration environment. Inthis point, the cellulose composite of the present invention isdifferent from conventional cellulose materials.

A food product using the cellulose composite of the present inventionmay be prepared by adding a main raw material, if necessary, by blendinga flavor, a pH moderator, a thickening stabilizer, salts, saccharides,fats and oil, proteins, an emulsifier, an acidulant and a dye, andapplying an operation such as mixing, kneading, stirring, emulsifyingand heating by use of the same apparatus as generally used in producingfoods.

Particularly, the cellulose composite of the present invention has ahigh storage elastic modulus (G′). Thus, even if a small amount ofcellulose composite is added, the cellulose composite provides excellentsuspension stability at a low viscosity. The cellulose composite isparticularly preferable as a suspension stabilizer for rich-tastebeverages containing a component such as coffee, cocoa and a tea extractin a high concentration.

<Method for Adding Cellulose Composite>

As a method for adding the cellulose composite of the present inventionto a food and drink, the following method is mentioned. The cellulosecomposite of the present invention can be added by dispersing it inwater simultaneously with a main raw-material or components such as acoloring agent, a spice, an acidulant and a thickener.

Furthermore, when dry powder of a cellulose composite is dispersed in anaqueous medium, it is preferable that the cellulose composite is oncedispersed in water and then added to a desired food form. This isbecause the suspension stability of the cellulose composite is improved.When the cellulose composite is dry powder, the cellulose composite canbe dispersed in water by a method of using a kneading machine includingvarious types of dispersion machines, emulsifiers and grinders usuallyused in production step of foods. Specific examples of the kneadingmachine that can be used include various types of mixers such as apropeller stirrer, a high-speed mixer, a homo mixer and a cutter; millssuch as a ball mill, a colloidal mill, a beads mill and a grinder(Raikai mixer); dispersers/emulsifiers represented by high-pressurehomogenizer such as high pressure homogenizer and a nanomizer; andkneading machines represented by e.g., a planetary mixer, kneader,extruder and turbulizer. The kneading machines may be used incombination of two types or more. Furthermore, dispersion can be easilymade if kneading is performed while increasing the temperature.

<Additive Amount to Food and Drink>

The additive amount of cellulose composite to a food and drink is notparticularly limited. For example, the additive amount of cellulosecomposite to beverages such as coffee, cocoa and milk is preferably 0.01mass % or more. If the additive amount of cellulose composite is 0.01mass % or more, dispersion and suspension stability increases, excellentemulsion stability and syneresis prevention effect can be obtained. Theadditive amount of cellulose composite is more preferably 0.05 mass % ormore and further preferably 0.1 mass % or more. If the additive amountof cellulose composite is 5 mass % or less, aggregation and separationof the cellulose composite do not occur. Also in view of easy-to-take asa beverage (feeling in the throat, grainy feeling on the tongue), theadditive amount is preferably 5 mass % or less.

<Water-Insoluble Component>

The cellulose composite of the present invention is particularlypreferable for use in neutral foods and drinks containingwater-insoluble components. The water-insoluble component refers to acomponent not dissolved in water and refers, in the present invention,to a component that can pass through a sieve having an opening of 10 mm,more preferably a sieve with 5 mm opening and further preferably a sievewith 2 mm opening. The water-insoluble component becomes unstable in aneutral condition; however, excellent suspension stability is acquiredif the cellulose composite of the present invention is added.

As the water-insoluble component, a component having a density of 1.0g/mL or more is preferable. Since the density is high, thewater-insoluble component is rich in nutrient such as carbohydrate andmineral. The density can be obtained by dispersing a water-insolublecomponent in ion-exchanged water, centrifugally treating (12000G×60minutes, where G represents a gravitational acceleration) and thereaftermaking a calculation based on the ratio of volume increase of the wholedispersion solution and increase of mass (mass increase/volumeincrease). The higher the density, the easier the nutrient intake. Thusthe density is preferably high, more preferably 1.1 g/mL or more,further preferably 1.2 g/mL or more and particularly preferably 1.5 g/mLor more. The upper limit is preferably 3 g/mL or less since thewater-insoluble component is easily chewed.

Examples of the water-insoluble component include proteins and fruitpieces contained in cocoa powder, cereal powder, food and drink;lactobacillus contained in lactobacillus beverages and the like; pulpcomponents and the like contained in vegetable juice beverages;functional food materials having a larger specific gravity than watersuch as milk calcium, calcium carbonate, magnesium and zinc or saltsthereof, beta-glucan and proteins (soybean protein, milk protein,collagen), turmeric and lychee; functional food materials having asmaller specific gravity than water such as ubidecarenone compounds suchas coenzyme Q10, omega 3 compounds such as docosahexaenoic acid,eicosapentaenoic acid or esters thereof, and ceramide compounds.

As the water-insoluble component to be used and blended in the presentinvention, particularly, cereal is preferable.

The additive amount of functional food material as mentioned abovevaries depending upon the amount of intake of beverages per day and theefficacy of the material; however, a functional food material ispreferably added in an amount of 0.01 mass % or more based on thebeverage, more preferably 0.05 mass % or more, and further preferably0.1 mass % or more.

<Viscosity of Beverage>

The viscosity of a beverage of the present invention at 25° C. asmeasured by B type viscometer is preferably 3 to 700 mPa·s. If theviscosity falls within the range, the agglutination/sedimentation of acomponent can be suppressed and easy-to-take neutral foods and drinkscan be prepared. In view of this, the viscosity is more preferably 10 to400 mPa·s and further preferably 20 to 200 mPa·s.

<Viscoelasticity of Beverage>

Foods and drinks, medicinal products and industrial products of thepresent invention contain a cellulose composite and a water-insolublecomponent in an aqueous medium. As the viscoelasticity of theseproducts, a loss tangent, tan δ (loss elastic modulus G″/storage elasticmodulus G′), is 1.5 or more. The higher the loss tangent, the moresatisfactory taste and flavor (such as rich-taste) becomes when abeverage and the like is taken. Furthermore, the density of awater-insoluble component is preferably 1.0 g/mL or more.

The loss tangent tan δ herein, can be calculated from a storage elasticmodulus G′ and a loss elastic modulus G″ measured by a viscoelasticitymeasurement apparatus based on dependency of stress of a beverage upondistortion and in accordance with the following expression.

The distortion-dependent stress of the water dispersion is measured by aviscoelasticity measurement apparatus (ARES100FRTN1 type, manufacturedby Rheometric Scientific, Inc., geometry: Double Wall Couette type,sweeping is performed at a constant temperature at 25.0° C. and anangular velocity of 20 rad/second within a distortion range of 1 to794%); a water dispersion is slowly supplied by use of a dropper so asnot to destroy a microstructure of a cellulose composite in a beverageand allowed to stand still for 5 minutes and then measurement isinitiated by Dynamic Strain mode.loss tangent tan δ=loss elastic modulus G″/storage elastic modulusG′  Expression:

In the present invention, loss tangent tan δ is obtained from thestorage elastic modulus and loss elastic modulus corresponding to adistortion of 200% on the distortion-stress curve obtained by theaforementioned measurement. The loss tangent tan δ of the above beverageis preferably 1.6 or more, more preferably 1.7 or more, furtherpreferably 1.8 or more, particularly preferably 1.9 or more and mostpreferably 2 or more.

Note that, in the present invention, the aqueous medium refers to amedium consisting of water (60 mass % to 100 mass %) and a water solubleorganic solvent (0 mass % to 40 wt %), more preferably consisting ofwater (70 mass % to 100 mass %) and a water soluble organic solvent (0mass % to 30 wt %), further preferably consisting of water (80 mass % to100 mass %) and a water soluble organic solvent (0 mass % to 20 wt %)and particularly preferably consisting of water (90 mass % to 100 mass%) and a water soluble organic solvent (0 mass % to 10 wt %). Examplesof the water soluble organic solvent include alcohols such as methanol,ethanol, propanol, isopropanol, butanol and pentanol; ketones such asacetone and methylethylketone; and polyethylene glycol. When the watersoluble organic solvent is used in food, an alcohol such as ethanol thatcan be orally ingested can be preferably used. In the case of medicinalproducts, polyethylene glycol that can improve absorption of a medicinalproducts, can be preferably used.

<Highly Concentrated Cocoa Beverage>

The cellulose composite of the present invention is preferably used inrich-taste cocoa beverages which is high in cacao concentration. Thehighly concentrated cocoa beverage herein is characterized in that acacao content (1.5 to 3.5 mass %) is added to a cocoa beverage. As thecacao content, a cocoa powder, a cacao powder and a cacao extract can beused singly or as a mixture having an arbitrary blending ratio.Particularly, if a cocoa powder having a high oil content (10 mass % ormore) is used in combination with cacao butter (0.15 mass % or more), arich-taste cocoa beverage having flavor and rich body can be obtained.In such a highly concentrated cocoa beverage, problems such asring-formation phenomena, separation of milk fat and sedimentation tendto occur. However, owing to addition of the cellulose composite of thepresent invention, these problems are overcome to obtain a cocoabeverage stably providing rich-taste, and generation of aggregatedsubstances can be suppressed even after retort sterilization or UHTsterilization. Furthermore, in cocoa beverages containing at least onemilk component selected from the group consisting of milk, concentratedmilk, whole powdered milk, powdered skim milk and condensed milk, acocoa beverage containing the milk components suppressed in generationof aggregated substances even after retort sterilization or UHTsterilization can be provided. The conditions of retort sterilizationand UHT sterilization herein are not particularly limited as long asthey can be usually used for cocoa beverages containing a milkcomponent. Generally, sterilization is performed within the range of120° C. to 145° C. for 15 seconds to 60 minutes.

<High Concentration Coffee Beverage>

The cellulose composite of the present invention is suitable for arich-taste coffee beverage having a high coffee concentration. Thecoffee beverage having a high coffee concentration herein is preferablya coffee beverage having a coffee content of 10 to 15 mass % in terms ofgreen coffee beans. Furthermore, the extraction rate of coffee beans ispreferably 15 to 35% and the coffee concentration (Brix value) of afinal coffee beverage is preferably 1.5 to 5.25. As a Brix value, avalue obtained by a refractometer (N-10E, manufactured by Atago Co.,Ltd.) can be used. Since a final coffee beverage contains e.g., sugarand proteins, the Brix value of coffee itself is determined byconversion based on the Brix value of a coffee extract measured and theadditive amount of the extract to a coffee beverage.

Furthermore, as the milk component used herein, milk, concentrated milk,whole powdered milk and powdered skim milk are particularly mentioned.In the present invention, owing to the addition of a highly functionalcellulose composite, generation of aggregated substances in a milkcomponent-containing coffee beverage containing a content of coffeecomponent beyond 10 mass % in terms of green beans can be suppressedeven after retort sterilization or UHT sterilization. Furthermore, evenif a coffee beverage containing at least one milk component selectedfrom the group consisting of milk, concentrated milk, whole powderedmilk, powdered skim milk and condensed milk, a milk content containingcoffee beverage suppressed from generation of aggregated substances evenafter retort sterilization or UHT sterilization can be provided. Theconditions of the retort sterilization and UHT sterilization herein arenot particularly limited as long as they are usually used for a coffeebeverage containing a milk component; however, sterilization isgenerally performed within the range of 120° C. to 145° C. for 15seconds to 60 minutes.

<Highly Concentrated Tea Beverage>

The cellulose composite of the present invention is suitable for arich-taste tea beverage having a high tea concentration. The teabeverage having a high tea concentration herein refers to a tea beveragehaving a caffeine content of 10 mg or more per tea beverage (100 mL),when the caffeine concentration of tea beverage which is a tea extractis measured. The tea beverages, from which caffeine is extracted in ahigh concentration, are preferable since they contain polyphenols suchas catechin and tannin in large amounts and thus an antioxidant effect,a sterilization effect and a physical condition improving effect can beobtained by drinking these. In addition, such teas visually emit a vividcolor intrinsic to tea such as green and brown. The caffeine hereinserves as an index for the concentration of these tea extracts.Accordingly, the caffeine concentration is more preferably 15 mg or moreper beverage (100 mL), further preferably 20 mg or more, particularlypreferably 30 mg or more and most preferably 40 mg or more. The higherthe concentration of a tea extract, the stronger the bitter taste andthe harder the tea is taken. Thus, the upper limit is 100 mg or less.

The term of the tea herein refers to an extract of tea, which isobtained by drying leaves and stems of plants to obtain raw materialsand extracting components from the raw materials with water or hotwater. Leaves and stems of an evergreen tree belongs to CamelliaCamellia are preferably used for a tea plant (scientific name: Camelliasinensis). These plant raw-materials can be classified in accordancewith the processing method as follows. Green tea (non-fermented tea) isa tea obtained without oxidative fermentation; white tea (weaklyfermented tea) is a tea obtained by shortly applying oxidativefermentation; and blue tea (semi-fermented tea) is a tea obtained byapplying oxidative fermentation to some extent, in which oolong tea isclassified. Red tea (completely fermented tea or fully fermented tea) isa tea obtained by complete oxidative fermentation; yellow tea (weakafterfermented tea) is a tea obtained by applying the same process as inwhite tea and thereafter weakly applying oxidative fermentation; andblack tea (afterfermented tea) is a tea obtained by fermenting green teain a general sense with Aspergillus oryzae, in which Pu-erh tea isclassified. Among them, green tea, blue tea and red tea are preferablyused for the tea beverage in the present invention in view of taste andflavor and content of a component good for heath.

Pigments extracted from these teas more or less fade away bysterilization, which is performed for storing beverages for a long time;however, the cellulose composite of the present invention has an effectof suppressing color fading during sterilization due to a heat shieldeffect of CMC-Na radially extending from a crystalline cellulose. Thecontent of a crystalline cellulose composite in a highly concentratedtea beverage is preferably 0.05 mass % or more, more preferably 0.1 mass% or more, further preferably 0.15 mass % or more, particularlypreferably 0.2 mass % or more and most preferably 0.3 mass % or more.The larger the content of the crystalline cellulose composite, the morethe color-fading prevention effect and suspension stabilization effectcan be obtained; however, when the concentration becomes high, itbecomes difficult to swallow. For the reason, the upper limit ispreferably 5 mass % or less, more preferably 3 mass % or less, furtherpreferably 2 mass % or less and particularly preferably 1 mass %.

To reduce bitter taste, a milk component including animal milk such ascow milk and goat milk and vegetable milk such as soy milk is preferablyblended to the beverage of the present invention. The concentration of amilk component can be determined based on the amount of protein in abeverage. The amount of protein is preferably 0.1 g or more per beverage(100 mL), more preferably 0.2 g or more per beverage (100 mL), furtherpreferably 0.3 g or more, particularly preferably 0.5 g or more and mostpreferably 1 g or more. The upper limit is set within the range notdamaging taste and flavor intrinsic to tea, preferably 3 g or less andmore preferably 2 g or less.

<Meal Alternative Beverage>

The meal alternative beverage refers to a beverage rich in nutrients,which contains beans and cereals in an aqueous medium and serves as analternative and a supplement for a meal such as breakfast. Thecrystalline cellulose composite of the present invention is excellent insuspension stability for a high-concentration carbohydrate and proteinand in preventing color fading, and thus it is suitably used for themeal alternative beverage.

As the beans and cereals contained in the meal alternative beverage ofthe present invention, the following ones are mentioned. As the beans,pulverized products or paste of seeds and fruits of plants of the legumefamily are preferably blended. As the seeds or fruits derived fromplants of the legume family, soy bean, azuki, common bean, lima bean,pea, scarlet runner, broad bean, cherry bean, chick-pea, greengram,lentil, locust bean, peanut, cluster bean, jack bean and pigeon pea canbe used. As the seeds or fruits except the legume family, coffee bean(Rubiaceae family), cacao (Sterculiaceae or Malvaceae family) andMexican jumping bean (Euphorbia family) can be used.

The cereal herein refers to pulverized products or paste of seeds orfruits of the gramineous plant, wheat and analogous grain plants.Examples of grains of the gramineous plant include sativa (Asian rice),japonica (Japan), javanica (Jave), indica (India), glaberrima (Africanrice), nerica (hybrid between Asian rice and African rise) and corn(Corn). Examples of wheat include barley (barley), sticky wheat (asticky kind of barley), hull-less barley (variant of barley), wheat(wheat), rye (rye), oat, oat wheat (oat), Job's tear (not seed butfruit), millet, Italian millet, Japanese millet, corn (Indian millet,kaoliang, sorghum), American millet, pearl millet, Kedong millet, Indianrice (between a wild plant and cultivated plant). Furthermore, examplesof the analogous grains include buckwheat, rye buckwheat, amaranth(amaranthus, amaranthus caudatus) and quinoa.

Since the cellulose composite of the present invention has excellentsuspension stability, it is possible to produce meal alternativebeverages containing these beans and grains rich in nutrient in highconcentrations.

As the beans suitable for the meal alternative beverage, soy bean,azuki, common bean, pea, broad bean, greengram and peanut are preferableand soy bean, azuki and peanut are more preferable.

As the grains suitable for the meal alternative beverage, sativa (Asianrice), japonica (Japan), javanica (Jave), indica (India) and corn arepreferable. As wheats, barley (barley), wheat (wheat), rye (rye) and oatwheat (oat) are preferable. As analogous grains, buckwheat ispreferable. More preferably sativa (Asian rice), javanica (Jave), indica(India), corn (corn), barley (barley), rye (rye) and oat wheat (oat) areused. Since these are rich in dietary fiber and minerals in addition toa carbohydrate, they are preferably used as a meal alternative.

The additive amount of the beans and cereals mentioned above, variesdepending upon the amount of intake per day and efficacy of nutrition ofthe material. The beans and cereals are preferably added in an amount of1 mass % or more relative to a beverage, more preferably 2 mass % ormore, further preferably 3 mass % or more and particularly preferably 5mass % or more. The upper limit of the content, which varies dependingupon the processing method for these and the viscosity of a finalbeverage, is preferably 20 mass % or less. In view of easiness indrinking, the upper limit is preferably 10 mass % or less.

Pigments of these beans and cereals more or less fade away bysterilization, which is performed for storing beverages for a long time;however, the cellulose composite of the present invention has an effectof suppressing color fading during sterilization due to a heat shieldeffect of CMC-Na radially extending from a crystalline cellulose. Thecontent of a crystalline cellulose composite in a meal alternativebeverage is preferably 0.05 mass % or more, more preferably 0.1 mass %or more, further preferably 0.15 mass % or more, particularly preferably0.2 mass % or more and most preferably 0.3 mass % or more. The largerthe content of the crystalline cellulose composite, the more thecolor-fading prevention effect and suspension stabilization effect canbe obtained; however, when the concentration becomes high, it becomesdifficult to swallow. For the reason, the upper limit is preferably 5mass % or less, more preferably 3 mass % or less, further preferably 2mass % or less and particularly preferably 1 mass %.

To reduce bitter taste, a milk component including animal milk such ascow milk and goat milk and vegetable milk such as soy milk is preferablyblended to the beverage of the present invention. The concentration of amilk component can be determined based on the amount of protein in abeverage. The amount of protein is preferably 0.1 g or more per beverage(100 mL), more preferably 0.2 g or more per beverage (100 mL), furtherpreferably 0.3 g or more, particularly preferably 0.5 g or more and mostpreferably 1 g or more. The upper limit is set within the range notdamaging taste and flavor of materials, preferably 3 g or less, and morepreferably 2 g or less.

<Use Other than Food>

The cellulose composite of the present invention is significantlyimproved in colloid dispersibility and can be applied to, other thanfoods, medicinal products such as a syrup agent, a liquid agent and anointment; cosmetics such as a lotion, an emulsion and a cleaner; rawmaterials for cleaners and treatment agents for food and industrial use,raw materials for detergents for household use (clothes, a kitchen, ahouse, tableware, etc.), paints, pigments, ceramics, water based latex,agents for emulsification (polymerization), agents for agriculture,agents for fiber processing (refinement agent, dyeing assistant,softener, water repellent), soil-release finishing agents, concreteadmixtures, printing inks, lubrication oils, antistatic agents, antifogadditives, lubricants, dispersants, deinking agents, etc. Among these,particularly, in a composition of an aqueous suspension state containinga water-insoluble component, a stable dispersion state can be maintainedwithout causing aggregation, separation, syneresis and sedimentation.Furthermore, the cellulose composite is significantly improved inperformance as a stabilizer and a problem of grainy feeling can beovercome by its smooth feeling on the tongue and body. Therefore, thecellulose composite can be used in a wide variety of foods other thanthose described above.

EXAMPLES

The present invention is described by way of the following Examples.However, these should not be construed as limiting the scope of thepresent invention.

<Average Polymerization Degree of Cellulose>

The average polymerization degree of cellulose was measured by a reducedspecific viscosity method using a copper ethylene diamine solution,which is defined in the crystalline cellulose identification test (3) of“the 14th edition of the Japanese Pharmacopoeia” (published by HirokawaShoten K.K.).

<Viscosity of Sodium Carboxymethylcellulose (CMC-Na)>

(1) CMC-Na powder was dispersed in pure water in a concentration of 2mass % by use of a high-shear homogenizer (trade name “Excel autohomogenizer ED-7” manufactured by Nippon Seiki Co., Ltd., treatmentconditions: rotation number of 15,000 rpm×5 minutes) to prepare anaqueous solution.(2) Three hours after the dispersion (stored at 25° C.), the obtainedaqueous solution was set in B-type viscometer (rotor revolving speed: 60rpm), allowed to stand still for 60 seconds and rotated for 30 seconds,and then, a viscosity was measured. Note that, the rotor can beappropriately changed depending upon the viscosity.<Viscosity of Water Dispersion of Cellulose Composite>

A cellulose composite was dispersed in pure water by use of a high-shearhomogenizer (trade name “Excel auto homogenizer ED-7” manufactured byNippon Seiki Co., Ltd., treatment conditions: rotation number of 15,000rpm×5 minutes) to prepare 1.0 mass % pure water dispersion. Three hoursafter the dispersion (stored at 25° C.), the obtained water dispersionwas set in B-type viscometer (rotor revolving speed: 60 rpm), allowed tostand still for 30 seconds and rotated for 30 seconds, and then aviscosity was measured. Note that, the rotor can be appropriatelychanged depending upon the viscosity. The rotors used herein were asfollows: 1 to 20 mPa·s: BL type, 21 to 100 mPa·s: No. 1, 101 to 300mPa·s: No. 2, 301 mPa·s or more: No. 3).

<Molecular-Weight Distribution of CMC-Na>

(1) First, CMC-Na was dissolved in a 0.05 mol/L aqueous sodium hydroxidesolution in a concentration of 0.5 mass %.

(2) Then, the CMC-Na solution (5 μL) was injected in high performanceliquid chromatographic apparatus (trade name LC-20A type manufactured byShimadzu Corporation), to which a single column (trade name TSK-GELG5000PW type (7.8 mm×30 cm), manufactured by Tosoh Corporation) and twocolumns (trade name TSK-GEL G3000 PWXL type (7.8 mm×30 cm)) areconnected in line. Measurement is performed by supplying an aqueous 0.05mol/L aqueous sodium hydroxide solution as a mobile phase, at a flowrate of 1 mL/minute and setting a column temperature at 30° C. Detectionis made by a UV detector (wavelength: 210 nm).(3) From the obtained chromatogram, the number of peaks was visuallycounted.

FIG. 3 shows a GPC chromatogram of CMC-Na used for production ofExamples 1, 3 to 5. Two peaks (bimodal), i.e., a peak derived fromCMC-Na of a low molecular weight (viscosity 25 mPa·s) at a retentiontime of 16 to 24 minutes and a peak derived from CMC-Na of a highmolecular weight (viscosity 620 mPa·s) at 6 to 16 minutes were detected.Note that, the peak detected at 11 minutes is an unidentified peak,which is not derived from CMC-Na.

FIG. 4 shows a GPC chromatogram of CMC-Na used for production of Example2. Two peaks (bimodal), i.e., a peak derived from CMC-Na of a lowmolecular weight (viscosity 25 mPa·s) at a retention time of 14 to 24minutes and a peak derived from CMC-Na of a high molecular weight(viscosity 7000 mPa·s) at 4 to 13 minutes were detected. Note that, thepeak detected at 11 minutes is an unidentified peak, which is notderived from CMC-Na.

FIG. 5 shows a GPC chromatogram of CMC-Na used for production of Example8. Two peaks (bimodal), i.e., a peak derived from CMC-Na of a lowmolecular weight (viscosity 50 mPa·s) at a retention time of 19 to 23minutes and a peak derived from CMC-Na of a high molecular weight(viscosity 500 mPa·s) at 14 to 19 minutes were detected.

<Substitution Degree of CMC-Na>

(1) CMC-Na (anhydride) (0.5 g) was accurately weighed, wrapped with afilter and baked in a magnetic crucible into ash. After cooling, thiswas transferred to a 500 mL beaker. To the beaker, water (about 250 mL)and 0.05 M sulfuric acid (35 mL) were added and the obtained mixture wasboiled for 30 minutes. The resultant mixture was cooled and aphenolphthalein indicator was added. Excessive acid was neutralized byback titration with 0.1 M potassium hydroxide. The substitution degreewas calculated by the following expressions.A=((af−bf1)/sample anhydride (g))−alkali level (or +acid level)Substitution degree=(162×A)/(10000−80A)whereA: Amount of 0.05 M sulfuric acid (mL) consumed by alkali per sample (1g)a: Use amount of 0.05 M sulfuric acid (mL)f: Titer of 0.05 M sulfuric acidb: Titer (mL) of 0.1 M potassium hydroxidef1: Titer of 0.1 M potassium hydroxide162: Molecular weight of glucose80: Molecular weight of CH₂COONa—H

Method of Measuring Alkali Level (or Acid Level):

A sample (anhydride) (1 g) was accurately weighed in a 300 mL-flask. Tothis flask, water (about 200 mL) was added to dissolve the sample. Tothis, 0.05 M sulfuric acid (5 mL) was added and the mixture was boiledfor 10 minutes and cooled. To this resultant mixture, a phenolphthaleinindicator was added and titrated with 0.1 M potassium hydroxide (S mL).At the same time, a blank test was performed (B mL). The alkali levelwas calculated in accordance with the following expression.Alkali level=((B−S)×f)/sample anhydride (g)wheref: Titer of 0.1 M potassium hydroxide. If a value of {(B−S)×f} was anegative value (−), the alkali level was regarded as an acid level.<Method for Measuring Storage Elastic Modulus of Cellulose Composite>(1) A cellulose composite was dispersed in pure water by a high-shearhomogenizer (trade name “Excel autohomogenizer ED-7” manufactured byNippon Seiki Co., Ltd., treatment conditions: rotation number 15,000rpm×5 minutes) to prepare a pure water dispersion of 1.0 mass % inconcentration. Thereafter, the resultant water dispersion was allowed tostand still at room temperature for 3 days.(2) The distortion dependent stress of the water dispersion was measuredby a viscoelasticity measuring apparatus (ARES100FRTN1 type,manufactured by Rheometric Scientific, Inc., geometry: Double WallCouette type, distortion was swept in the range of 1 to 794%). In thepresent invention, as storage elastic modulus (G′), a valuecorresponding to a distortion of 20% on the distortion-stress curveobtained in the aforementioned measurement was used.<Content of Colloidal Cellulose Composite in Cellulose Composite>(1) A cellulose composite was suspended in pure water in a concentrationof 0.5 mass % and the resultant suspension was dispersed by a high-shearhomogenizer (trade name “Excel autohomogenizer ED-7”, manufactured byNippon Seiki Co., Ltd., treatment conditions: rotation number 15,000rpm×5 minutes).(2) The dispersion solution was centrifugally separated by a centrifuge(trade name “6800 type centrifuge” rotor-type RA-400, manufactured byKUBOTA Corporation, treatment conditions: centrifugal force of 39200m²/s) for 10 minutes. The supernatant was taken and furthercentrifugally treated at 116000 m²/s for 45 minutes.(3) After the centrifugation, the supernatant was fed into a glassweighing bottle and dried at 60° C. for 15 hours and thereafter at 105°C. for 2 hours. After a constant weight was obtained in a desiccator,the weight was measured. Separately, non-centrifuged water dispersionwas dried in the same manner and the weight was measured. From theresults, the mass percentage of the cellulose solid content remaining inthe supernatant was obtained in accordance with the followingexpression.Computation expression of content of colloidal cellulose composite:(solid content of the supernatant (50 g))/(solid content ofnon-centrifuged water dispersion (50 g))×100<Median Size of Colloidal Cellulose Composite Measured by Dynamic LightScattering Method>(1) A cellulose composite was suspended in pure water in a concentrationof 0.5 mass % and dispersed by a high-shear homogenizer (trade name“Excel auto homogenizer ED-7”, manufactured by Nippon Seiki Co., Ltd.,treatment conditions: rotation number of 15,000 rpm×5 minutes) andcentrifugally separated by a centrifuge (trade name “6800 typecentrifuge” rotor-type RA-400, manufactured by KUBOTA Corporation,treatment conditions: centrifugal force of 39200 m²/s) for 10 minutes.The supernatant was collected and further centrifugally treated at116000 m²/s for 45 minutes, and the resultant supernatant was collected.(2) The supernatant was placed in a 50-mL (volume) sample tube made ofPP and ultrasonically treated by an ultrasonic cleaner (an ultrasoniccleaner, trade name: AUC-1L type manufactured by AS ONE Corporation) for10 minutes.(3) Thereafter, a particle size distribution (frequency distribution ofscattering intensity versus particle size value) was measured by a zetapotential-particle size measurement system (trade name “ELSZ-2” (batchcell), manufactured by Otsuka Electronic Co., Ltd.). The median sizeherein refers to a particle size value (μm) corresponding to acumulative 50% scattering intensity in the frequency distribution.<Median Size of Colloidal Cellulose Composite Measured by the LaserDiffraction/Scattering Method (Particle Size of Cellulose Core ofCellulose Composite)>(1) A cellulose composite was suspended in pure water in a concentrationof 0.5 mass %, dispersed by a high-shear homogenizer (trade name “Excelauto homogenizer ED-7”, manufactured by Nippon Seiki Co., Ltd.,treatment conditions: rotation number of 15,000 rpm×5 minutes) andcentrifugally separated by a centrifuge (trade name “6800 typecentrifuge” rotor-type RA-400, manufactured by KUBOTA Corporation,treatment conditions: centrifugal force of 39200 m²/s) for 10 minutes.The supernatant was collected and further centrifugally treated at arate of 116000 m²/s for 45 minutes and the resultant supernatant wascollected.(2) The supernatant was measured by a laser diffraction/scatteringparticle size distribution meter (trade name “LA-910” manufactured byHoriba, Ltd. ultrasonic treatment: 1 minute, refractive index: 1.20). Inthe obtained volume frequency particle size distribution, the cumulative50% particle size (a volume average particle size) was obtained.<Median Size of Coarse Particles Measured by the LaserDiffraction/Scattering Method>(1) A cellulose composite was suspended in pure water in a concentrationof 0.5 mass %, dispersed by a high-shear homogenizer (trade name “Excelauto homogenizer ED-7”, manufactured by Nippon Seiki Co., Ltd.,treatment conditions: rotation number of 15,000 rpm×5 minutes).(2) The dispersion solution was measured as it is by a laserdiffraction/scattering particle size distribution meter (trade name“LA-910” manufactured by Horiba, Ltd. ultrasonic treatment: 1 minute,refractive index: 1.20). In the obtained volume frequency particle sizedistribution, the cumulative 50% particle size (volume average particlesize) was obtained.<Shape of Cellulose Particle (L/D)>

A cellulose composite was suspended in pure water in a concentration of1 mass % and dispersed by a high-shear homogenizer (trade name “Excelautohomogenizer ED-7” manufactured by Nippon Seiki Co., Ltd., treatmentconditions: rotation number 15,000 rpm×5 minutes). The resultant waterdispersion was diluted with pure water up to 0.1 mass % and a singledrop was casted on mica by use of a dropper. Excessive moisture contentwas blown out by an air duster and dried in the air to prepare a sample.An image was measured by an atomic force microscope (apparatus of NanoScope IV MM, manufactured by Digital Instruments, scanner EV, measuringmode Tapping, probe NCH type silicon single crystal probe). Based on theobtained image, the major axis (L) and the minor axis (D) of particleshaving a major axis (L) of 2 μm or less were measured. The shapes ofcellulose particles, which are defined by the ratio of (L/D), werecalculated as an average value of 100 to 150 particles.

<Structure of Cellulose Composite: Observation of Spread of aPolysaccharide from Cellulose>

A cellulose composite was dispersed in pure water by use of a high-shearhomogenizer (trade name “Excel auto homogenizer ED-7”, manufactured byNippon Seiki Co., Ltd., treatment conditions: rotation number of 15,000rpm×5 minutes, total amount 300 g) to prepare a 1.0 mass % pure waterdispersion. The obtained water dispersion was allowed to stand still for3 days or more at room temperature. Thereafter, the water dispersion wasdiluted 20 folds with pure water to prepare a sample solution. Analiquot (5 μl) was slowly suctioned so as not to destroy themicrostructure of a water dispersion by use of a dropper and slowlyadded dropwise on a mica cut piece of 1 cm×1 cm. Extra moisture wasblown away by an air duster and the sample fixed on the mica wasobserved by AFM (scanning probe microscope SPM-9700 manufactured byShimadzu Corporation, phase mode, a probe OMCL-AC240TS manufactured byOlympus Corporation was used). In the observed image, it was found thata cellulose particle is a rod particle having a height of 2 nm or more,and that a polysaccharide having a height of less than 2 nm radiallyextends from the cellulose particle peripherally (FIG. 1: an AFM imageof cellulose composite D obtained in Example 4).

Example 1

Commercially available DP pulp was cut into pieces and hydrolyzed in 2.5mol/L hydrochloric acid at 105° C. for 15 minutes, washed with water andthen filtrated to prepare a wet-cake like cellulose having a solidcontent of 50 mass % (average polymerization degree was 220).

Next, wet-cake like cellulose, commercially available CMC-Na (theviscosity of 2% solution: 620 mPa·s, substitution degree: 0.7 to 0.8) asComponent A, and commercially available CMC-Na (the viscosity of 2%solution: 25 mPa·s, substitution degree: 0.7 to 0.8) as Component B wereprepared. They were put in a planetary mixer (5DM-03-R, manufactured byShinagawa Machinery Works Co., Ltd., agitating blade was hook type) suchthat the mass ratio of cellulose (hereinafter referred to as MCC)/CMC-Na(Component A+Component B) became 90/10 (where constitution of CMC-Na:Component A/Component B=50/50) and water was added so as to obtain asolid content of 45 mass %.

Thereafter, the mixture was kneaded at 126 rpm to obtain cellulosecomposite A. The kneading energy was controlled according to kneadingtime in the planetary mixer and actual measurement value thereof was 390Wh/kg. As the kneading temperature, the temperature of the kneadedmixture was directly measured by a thermocouple. The kneadingtemperature was 20 to 40° C. throughout the kneading.

The storage elastic modulus (G′) of the resultant cellulose composite Awas 5.5 Pa. Furthermore, Particle L/D of the cellulose composite A was1.6; the content of the colloidal cellulose composite was 78 mass %; themedian size measured by a dynamic light scattering method of thecolloidal cellulose composite was 2.5 μm; the median size measured by alaser diffraction/scattering method was 0.13 μm; and the median size ofcoarse particles was 6.5 μm. The viscosity of a water dispersion of thecellulose composite was 383 mPa·s.

The results are shown in Table 1.

Example 2

Using chipped commercially available DP pulp, cellulose was hydrolyzedin the same manner as in Example 1. Subsequently, wet-cake likecellulose (average polymerization degree: 220), commercially availableCMC-Na (the viscosity of 2% solution: 7000 mPa·s, substitution degree:0.7 to 0.8) as Component A, and commercially available CMC-Na (theviscosity of 2% solution: 25 mPa·s, substitution degree: 0.7 to 0.8) asComponent B were prepared. MCC and Components A and B were added suchthat the mass ratio of MCC/CMC-Na (Component A+Component B) became 52/48(where constitution of CMC-Na: Component A/Component B=10/90), and waterwas added so as to obtain a solid content of 45 mass %. The mixture waskneaded in the same manner as in Example 1 to obtain cellulose compositeB. Kneading energy was controlled depending upon the kneading time of aplanetary mixer and an actual value thereof was 220 Wh/kg. The kneadingtemperature of the kneading mixture, which was directly measured by useof a thermocouple, was 20 to 40° C. throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Bwas 1.4 Pa; particle L/D was 1.6; the content of the colloidal cellulosecomposite was 69 mass %; the median size measured by a dynamic lightscattering method of the colloidal cellulose composite was 1.2 μm; themedian size measured by a laser diffraction/scattering method was 0.13μm; and the median size of coarse particles was 9.3 μm. The viscosity ofa water dispersion of the cellulose composite was 252 mPa·s.

The results are shown in Table 1.

Example 3

Using chipped commercially available DP pulp, cellulose was hydrolyzedin the same manner as in Example 1. Subsequently, wet-cake likecellulose (average polymerization degree: 220), commercially availableCMC-Na (the viscosity of 2% solution: 620 mPa·s, substitution degree:0.7 to 0.8) as Component A, and commercially available CMC-Na (theviscosity of 2% solution: 25 mPa·s, substitution degree: 0.7 to 0.8) asComponent B were prepared. MCC and Components A and B were added suchthat the mass ratio of MCC/CMC-Na (Component A+Component B) became 80/20(where constitution of CMC-Na: Component A/Component B=40/60), and waterwas added so as to obtain a solid content of 40 mass %. The mixture waskneaded in the same manner as in Example 1 to obtain cellulose compositeC. Kneading energy was controlled depending upon the kneading time of aplanetary mixer and an actual value thereof was 190 Wh/kg. The kneadingtemperature was controlled by cooling a jacket and the temperature ofthe kneading mixture, which was directly measured by use of athermocouple, was 20 to 60° C. throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Cwas 2.3 Pa; particle L/D was 1.6; the content of the colloidal cellulosecomposite was 67 mass %; the median size of the colloidal cellulosecomposite measured by a dynamic light scattering method was 1.1 μm; themedian size measured by a laser diffraction/scattering method was 0.13μm; and the median size of coarse particles was 8.2 μm. The viscosity ofa water dispersion of the cellulose composite was 182 mPa·s.

The results are shown in Table 1.

Example 4

Using commercially available KP pulp, cellulose was hydrolyzed in thesame manner as in Example 1. Subsequently, wet-cake like cellulose(average polymerization degree: 220), commercially available CMC-Na (theviscosity of 2% solution: 620 mPa·s, substitution degree: 0.7 to 0.8) asComponent A, and commercially available CMC-Na (the viscosity of 2%solution: 25 mPa·s, substitution degree: 0.7 to 0.8) as Component B wereprepared. MCC and Components A and B were added such that the mass ratioof MCC/CMC-Na (Component A+Component B) became 90/10 (where constitutionof CMC-Na: Component A/Component B=40/60), and water was added so as toobtain a solid content of 50 mass %. The mixture was kneaded in the samemanner as in Example 1 to obtain cellulose composite D. Kneading energywas controlled depending upon the kneading time of a planetary mixer andan actual value thereof was 100 Wh/kg. The kneading temperature wascontrolled by cooling a jacket and the temperature of the kneadingmixture, which was directly measured by use of a thermocouple, was 20 to65° C. throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Dwas 2.5 Pa; particle L/D was 1.6; the content of the colloidal cellulosecomposite was 72 mass %; the median size measured by a dynamic lightscattering method of the colloidal cellulose composite was 1.2 μm; themedian size measured by a laser diffraction/scattering method was 0.13μm; and the median size of coarse particles was 9.1 μm. The viscosity ofa water dispersion of the cellulose composite was 220 mPa·s.

The results are shown in Table 1.

Example 5

Using chipped commercially available DP pulp, cellulose was hydrolyzedin the same manner as in Example 1. Subsequently, wet-cake likecellulose (average polymerization degree: 220), commercially availableCMC-Na (the viscosity of 2% solution: 620 mPa·s, substitution degree:0.7 to 0.8) as Component A, and commercially available CMC-Na (theviscosity of 2% solution: 25 mPa·s, substitution degree: 0.7 to 0.8) asComponent B were prepared. Other than MCC and CMC-Na, xanthan gum as awater soluble gum and dextrin as a hydrophilic substance were blended.MCC, Components A and B, xanthan gum and dextrin were added such thatthe mass ratio of MCC/CMC-Na (Component A+Component B)/xanthangum/dextrin became 70/5/5/20 (where constitution of CMC-Na: ComponentA/Component B=50/50), and water was added so as to obtain a solidcontent of 45 mass %. The mixture was kneaded in the same manner as inExample 1 to obtain cellulose composite E. Kneading energy wascontrolled depending upon the kneading time of a planetary mixer and anactual value thereof was 80 Wh/kg. The kneading temperature wascontrolled by cooling a jacket and the temperature of the kneadingmixture, which was directly measured by use of a thermocouple, was 20 to65° C. throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Ewas 1.2 Pa; particle L/D was 1.6; the content of the colloidal cellulosecomposite was 75 mass %; the median size measured by a dynamic lightscattering method of the colloidal cellulose composite was 0.95 μm; themedian size measured by a laser diffraction/scattering method was 0.16μm; and the median size of coarse particles was 8.5 μm. The viscosity ofa water dispersion of the cellulose composite was 140 mPa·s.

The results are shown in Table 1.

Example 6

Using chipped commercially available DP pulp, cellulose was hydrolyzedin the same manner as in Example 1. Subsequently, wet-cake likecellulose (average polymerization degree: 220) and commerciallyavailable CMC-Na (the viscosity of 2% solution: 25 mPa·s, substitutiondegree: 0.7 to 0.8) as Component B were prepared. Component A was notadded. MCC and CMC-Na (Component B) were added such that the mass ratioof MCC/CMC-Na (Component B) became 90/10 (where constitution of CMC-Na:Component A/Component B=0/100), and water was added so as to obtain asolid content of 45 mass %. The mixture was kneaded in the same manneras in Example 1 to obtain cellulose composite F.

Kneading energy was controlled depending upon the kneading time of aplanetary mixer, an actual value thereof was 200 Wh/kg. The kneadingtemperature was controlled by cooling a jacket and measured by use of athermocouple. The mixture was kneaded at 50° C. or less until thekneading energy reached 30 Wh/kg. Thereafter, the kneaded mixture wascooled by cooling the jacket and the temperature of the kneaded mixturewas 15° C. or less throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Fwas 1.0 Pa; particle L/D was 1.6; the content of the colloidal cellulosecomposite was 78 mass %; the median size measured by a dynamic lightscattering method of the colloidal cellulose composite was 0.85 μm; themedian size measured by a laser diffraction/scattering method was 0.13μm; and the median size of coarse particles was 7.8 μm. The viscosity ofa water dispersion of the cellulose composite was 175 mPa·s.

The results are shown in Table 1.

Comparative Example 1

Using chipped commercially available DP pulp, cellulose was hydrolyzedin the same manner as in Example 1. Subsequently, wet-cake likecellulose (average polymerization degree: 220) and commerciallyavailable CMC-Na (the viscosity of 2% solution: 620 mPa·s, substitutiondegree: 0.7 to 0.8) as Component A were added without adding Component Bsuch that the mass ratio of MCC/CMC-Na (Component A+Component B) became90/10 (where constitution of CMC-Na: Component A/Component B=100/0), andwater was added so as to obtain a solid content of 37 mass %. Themixture was kneaded in the same manner as in Example 1 to obtaincellulose composite G. Kneading energy was controlled depending upon thekneading time of a planetary mixer and an actual value thereof was 60Wh/kg. The kneading temperature was controlled by cooling a jacket andthe temperature of the kneading mixture, which was directly measured byuse of a thermocouple, was 20 to 85° C. throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Gwas 0.45 Pa; particle L/D was 1.6; the content of the colloidalcellulose composite was 70 mass %; the median size measured by a dynamiclight scattering method of the colloidal cellulose composite was 0.81μm; the median size measured by a laser diffraction/scattering methodwas 0.13 μm; and the median size of coarse particles was 9.5 μm. Theviscosity of a water dispersion of the cellulose composite was 98 mPa·s.

The results are shown in Table 1.

Comparative Example 2

Commercially available DP pulp was cut into pieces and hydrolyzed in 10mass % hydrochloric acid at 105° C. for 20 minutes. The acid insolubleresidue obtained by the hydrolysis was filtrated and washed to prepare acellulose water dispersion having a solid content of 10 mass % (averagepolymerization degree was 200). The volume average particle size of thehydrolysis cellulose was 17 μm. The cellulose water dispersion wassubjected twice to a pulverizing process performed by a medium stirringwet-process pulverization apparatus (apex mill, AM-1 type, manufacturedby Kotobuki Engineering & Manufacturing Co., Ltd.) using zirconia beadshaving a diameter of 1 mm ϕ as a medium in the conditions where astirring blade rotation number was 1800 rpm and a cellulose waterdispersion supply amount was 0.4 L/min to obtain micro cellulose paste.

A paste-like micro cellulose/CMC-Na (substitution degree: 0.90,viscosity: 7 mPa·s) were weighed so as to satisfy a mass ratio of 80/20.To this mixture, pure water was added so as to satisfy a total solidcontent concentration of 11 mass %. The resultant mixture was dispersedby a TK homo mixer (MARKII, manufactured by Tokushu Kika Kogyo Co.,Ltd.) at 8,000 rpm for 20 minutes to prepare a paste-like waterdispersion (as the kneading energy was calculated from power consumptionof the apex mill and TK homogenizer and a treatment amount, it was 30Wh/kg. The kneading temperature, which was measured in the same manneras in Example 1, was 20 to 60° C. throughout the kneading and theachieving temperature was 50 to 60° C.).

The water dispersion was dried by a drum dryer (KDD-1 type, manufacturedby Kusunoki Kikai Seisakusho) at a water vapor pressure of 2 Kg/cm², arotation number of 0.6 rpm, scratched out by a scraper and roughlypulverized by a flush mill (manufactured by Fuji Paudal Co., Ltd.) toobtain thin slice or scale like cellulose composite H. The kneadingenergy was 0.03 kWh/kg.

The storage elastic modulus (G′) of the obtained cellulose composite Hwas 0.38 Pa; particle L/D was 1.3; the content of the colloidalcellulose composite was 91 mass %; the median size measured by a dynamiclight scattering method of the colloidal cellulose composite was 0.65μm; the median size measured by a laser diffraction/scattering methodwas 0.11 μm; and the median size of coarse particles was 3.4 μm. Theviscosity of a water dispersion of the cellulose composite was 80 mPa·s.

The results are shown in Table 1.

Comparative Example 3

Using chipped commercially available DP pulp, cellulose was hydrolyzedin the same manner as in Example 1. Subsequently, wet-cake likecellulose (average polymerization degree: 220) and commerciallyavailable CMC-Na (the viscosity of 2% solution: 7 mPa·s, substitutiondegree: 0.7 to 0.8) as Component B were added without adding Component Asuch that the mass ratio of MCC/CMC-Na (Component B) became 90/10 (whereconstitution of CMC-Na: Component A/Component B=0/100), and water wasadded so as to obtain a solid content of 40 mass %. The mixture waskneaded in the same manner as in Example 1 to obtain cellulose compositeI. Kneading energy was controlled depending upon the kneading time of aplanetary mixer and an actual value thereof was 60 Wh/kg. The kneadingtemperature was controlled by cooling a jacket and the temperature ofthe kneading mixture, which was directly measured by use of athermocouple, was 20 to 85° C. throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Iwas 0.41 Pa; particle L/D was 1.6; the content of the colloidalcellulose composite was 70 mass %; the median size measured by a dynamiclight scattering method of the colloidal cellulose composite was 0.69μm; the median size measured by a laser diffraction/scattering methodwas 0.13 μm; and the median size of coarse particles was 9.3 μm. Theviscosity of a water dispersion of the cellulose composite was 75 mPa·s.

The results are shown in Table 1.

Example 7

Using chipped commercially available DP pulp, cellulose was hydrolyzedin the same manner as in Example 1. Subsequently, wet-cake likecellulose (average polymerization degree: 220) and commerciallyavailable CMC-Na (the viscosity of 2% solution: 50 mPa·s, substitutiondegree: 1.3) as Component B were prepared. Component A was not added.MCC and CMC-Na (Component B) were added such that the mass ratio ofMCC/CMC-Na (Component B) became 90/10 (where constitution of CMC-Na:Component A/Component B=0/100), and water was added so as to obtain asolid content of 46 mass %. The mixture was kneaded in the same manneras in Example 1 to obtain cellulose composite J.

Kneading energy was controlled depending upon the kneading time of aplanetary mixer, an actual value thereof was 200 Wh/kg. The kneadingtemperature was controlled by cooling a jacket and measured by use of athermocouple. The mixture was kneaded at 50° C. or less until thekneading energy reached 30 Wh/kg. Thereafter, the kneaded mixture wascooled by cooling the jacket and the temperature of the kneaded mixturewas 15° C. or less throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Jwas 2.6 Pa; particle L/D was 1.6; the content of the colloidal cellulosecomposite was 78 mass %; the median size measured by a dynamic lightscattering method of the colloidal cellulose composite was 1.3 μm; themedian size measured by a laser diffraction/scattering method was 0.13μm; and the median size of coarse particles was 7.5 μm. The viscosity ofa water dispersion of the cellulose composite was 180 mPa·s.

The results are shown in Table 1.

Example 8

Using chipped commercially available DP pulp, cellulose was hydrolyzedin the same manner as in Example 1. Subsequently, wet-cake likecellulose (average polymerization degree: 220), commercially availableCMC-Na (the viscosity of 2% solution: 500 mPa·s, substitution degree:1.5) as Component A, and commercially available CMC-Na (the viscosity of2% solution: 50 mPa·s, substitution degree: 1.3) as Component B wereprepared. MCC and Components A and B were added such that the mass ratioof MCC/CMC-Na (Component A+Component B) became 92/8 (where constitutionof CMC-Na: Component A/Component B=25/75), and water was added so as toobtain a solid content of 48 mass %. The mixture was kneaded in the samemanner as in Example 1 to obtain cellulose composite K.

Kneading energy was controlled depending upon the kneading time of aplanetary mixer and an actual value thereof was 250 Wh/kg. The kneadingtemperature was controlled by cooling a jacket and measured by use of athermocouple. The mixture was kneaded at 50° C. or less until thekneading energy reached 30 Wh/kg. Thereafter, the kneaded mixture wascooled by cooling the jacket and the temperature of the kneaded mixturewas 40° C. or less throughout the kneading.

The storage elastic modulus (G′) of the obtained cellulose composite Kwas 4 Pa; particle L/D was 1.6; the content of the colloidal cellulosecomposite was 77 mass %; the median size measured by a dynamic lightscattering method of the colloidal cellulose composite was 2.2 μm; themedian size measured by a laser diffraction/scattering method was 0.13μm; and the median size of coarse particles was 7.8 μm. The viscosity ofa water dispersion of the cellulose composite was 330 mPa·s.

The results are shown in Table 1.

Examples, Comparative Examples: Cocoa Beverage

Using cellulose composites A to K obtained in Examples and ComparativeExamples as mentioned above, cocoa beverages were prepared by thefollowing operation and evaluated. Previously prepared by mixing powderraw materials: cocoa powder (30 g) (a powder mixture containing an oilcontent of 10 mass %, sugar (50 g), whole powdered milk (8 g), tablesalt (0.5 g) and an emulsifier (monoglyceride preparation) (1.0 g)), anda cellulose composite (4.0 g) were added. To this mixture, ion-exchangedwater warmed to 80° C. was added to obtain 1000 g. Thereafter, themixture was stirred by a propeller (500 rpm, 10 minutes), homogenized(at 10 MPa) by a piston homogenizer and transferred to a 200 mL-volumeheat-resistant glass bottle to obtain highly concentrated milk cocoa.This was subjected to heat sterilization treatment (121° C., 30 minutes)and cooled with service-water for one hour. Thereafter, the bottlecontainer was vertically gently shaken 10 times and allowed to standstill and stored in an atmosphere of 5° C. for one month. Appearance ofthe bottle was visually observed. The evaluation manner was as shownbelow and the obtained results are shown in Table 1.

<Suspension Stability: Observation of Appearance of Food and Drink>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were visually evaluatedbased on the criteria defined with respect to the following four items.

(Separation) evaluated based on the volume of an upper thin-color layerof beverage contained in a heat-resistant bottle.

⊚ (excellent): no separation, ◯ (good): separation is less than 10%, Δ(acceptable): separation is less than 30%, X (unacceptable): separationis 30% or more

(Sedimentation) evaluated based on the amount of deposited substance onthe bottom of a heat-resistant bottle containing a beverage.

⊚ (excellent): no sedimentation, ◯ (good): a partially thinsedimentation, Δ (acceptable): entirely thin sedimentation, X(unacceptable): entirely thick sedimentation

(Aggregation) evaluated based on the amount of non-homogeneous portionin the entire beverage contained in a heat-resistant bottle.

⊚ (excellent): homogeneous, ◯ (good): slightly partiallynon-homogeneous, Δ (acceptable): partially non-homogeneous, X(unacceptable): entirely non-homogeneous

(Oil ring) evaluated based on the amount of ring-form solidified matterof oil along the bottle wall at upper portion of beverage contained in aheat-resistant bottle

⊚ (excellent): none, ◯ (good): slightly partially formed, Δ(acceptable): incompletely ring shape formed, X (unacceptable):completely ring shape formed

<Viscosity of Beverage>*The Evaluation Criteria do not Apply to FoodsExcept Beverages

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were produced. One hourlater (stored at 25° C.), each of the beverages was set in a B-typeviscometer (rotor revolving speed: 60 rpm), allowed to stand still for30 seconds and rotated for 30 seconds, and then viscosity was measured.Note that the rotor can be appropriately changed depending upon theviscosity. The rotors used herein were as follows: 1 to 20 mPa·s: BLtype, 21 to 100 mPa·s: No. 1, 101 to 300 mPa·s: No. 2, 301 mPa·s: No.3). The measurement results were classified based on the followingcriteria.

(Viscosity) ⊚ (excellent): 1 to 10, ◯ (good): 10 to 20, Δ (acceptable):20 to 50, X (unacceptable): 50 or more [mPa·s]

<Texture>

The evaluation criteria of texture were as follows:

⊚ (excellent): light feeling in the throat and has appropriate body.

◯ (good): slightly sticky feeling in the throat.

Δ (acceptable): heavy feeling in the throat and sticky.

X (unacceptable): good feeling in the throat but watery.

<Taste: Rich Taste>

The evaluation criteria of taste were as follows:

⊚ (excellent): have satisfactory rich taste.

◯ (good): have rich taste.

Δ (acceptable): have slightly rich taste.

X (unacceptable): have no rich taste.

<Viscoelasticity of Beverage: Tan δ>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were produced. One daylater of the production, beverages were backed to normal temperature(25° C.) and each of the beverages was set in a viscoelasticitymeasuring apparatus (ARES100FRTN1 Type, manufactured by RheometricScientific, Inc., geometry: Double Wall Couette type, distortion wasswept in the range of 1 to 794%) to measure viscoelasticity. In thepresent invention, loss tangent tan δ (loss elastic modulus G″/storageelastic modulus G′) was obtained from the storage elastic modulus andloss elastic modulus corresponding to a distortion of 200% on thedistortion-stress curve obtained by the aforementioned measurement.

Examples, Comparative Examples: Highly Concentrated Coffee Beverage

Using cellulose composites A to K obtained in Examples and ComparativeExamples as mentioned above, coffee beverages were prepared by thefollowing operations and evaluated. Coffee powder (trade name: “PremiumBlend” manufactured by Key Coffee Inc.) (250 g) was weighted on filtercloth made of cotton flannel. Boiled hot water (2000 g) was pouredaround the coffee powder and a coffee extract through the filter clothwas collected. The extract was subjected to measurement of Brix by asaccharimeter (trade name “PAL-1”, manufactured by Atago Co., Ltd.). Asa result, Brix was 3.3.

Next, to the coffee extract (64.5 parts by mass), milk (13.0 parts bymass), granulated sugar (5.0 parts by mass), an emulsifier (trade name“sucrose fatty acid ester P-1670”, manufactured by Mitsubishi KagakuFoods Corporation) (0.03 parts by mass), sodium hydrogen carbonate(special grade, manufactured by Wako Pure Chemical Industries Ltd.)(0.45 parts by mass) and each of cellulose composites A to K (0.05 partsby mass) were added. To this mixture, pure water was added to obtain atotal of 100 parts by mass. Thereafter, the mixture was transferred to a2 L-volume container made of stainless steel and stirred (300 rpm, 10minutes) at 80° C. by a propeller. Thereafter, the dispersion solutionwas homogenized by a piston homogenizer (trade name: “Manton-GaulinHomogenizer” manufactured by APV) (20 MPa). This was subjected to UHTheat sterilization treatment (140° C., 60 seconds), transferred to a 200mL-volume heat-resistant glass bottle, closed tightly, and cooled withtap-water for one hour. Thereafter, the container (bottle) wasvertically gently shaken 10 times, allowed to stand still and stored inan atmosphere of 60° C. for 28 days. Appearance of the beverage wasvisually observed. The evaluation manner was as follows. The obtainedresults are shown in Table 1.

<Suspension Stability: Observation of Appearance of Food and Drink>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were visually evaluatedbased on the criteria defined with respect to the following four items.

(Separation) evaluated based on the volume of an upper thin-color layerof beverage contained in a heat-resistant bottle.

⊚ (excellent): no separation, ◯ (good): separation is less than 10%, Δ(acceptable): separation is less than 30%, X (unacceptable): separationis 30% or more

(Sedimentation) evaluated based on the amount of deposited substance onthe bottom of a heat-resistant bottle containing a beverage.

⊚ (excellent): no sedimentation, ◯ (good): a partially thinsedimentation, Δ (acceptable): entirely thin sedimentation, X(unacceptable): entirely thick sedimentation

(Aggregation) evaluated based on the amount of non-homogeneous portionin the entire beverage contained in a heat-resistant bottle.

⊚ (excellent): homogeneous, ◯ (good): slightly partiallynon-homogeneous, Δ (acceptable): partially non-homogeneous, X(unacceptable): entirely non-homogeneous

(Oil ring) evaluated based on the amount of ring-form solidified matterof oil along the wall of a bottle observed at upper portion of beveragecontained in a heat-resistant bottle

⊚ (excellent): none, ◯ (good): slightly partially formed, Δ(acceptable): incompletely ring shape formed, X (unacceptable):completely ring shape formed

<Viscosity of Beverage*The Evaluation Criteria do not Apply to FoodsExcept Beverages.>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were produced. One hourlater (stored at 25° C.), each of the beverages was set in a B-typeviscometer (rotor revolving speed: 60 rpm), allowed to stand still for30 seconds and rotated for 30 seconds, and then viscosity was measured.Note that the rotor can be appropriately changed depending upon theviscosity. The rotors used herein were as follows: 1 to 20 mPa·s: BLtype, 21 to 100 mPa·s: No. 1, 101 to 300 mPa·s: No. 2, 301 mPa·s: No.3). The measurement results were classified based on the followingcriteria.

(Viscosity) ⊚ (excellent): 1 to 10, ◯ (good): 10 to 20, Δ (acceptable):20 to 50, X (unacceptable): 50 or more [mPa·s]

<Texture>

The evaluation criteria of texture were as follows:

⊚ (excellent): light feeling in the throat and has appropriate body.

◯ (good): slightly sticky feeling in the throat.

Δ (acceptable): heavy feeling in the throat and sticky.

X (unacceptable): good feeling in the throat but watery.

<Taste: Rich Taste>

The evaluation criteria of taste were as follows:

⊚ (excellent): have satisfactory rich taste.

◯ (good): have rich taste.

Δ (acceptable): have slightly rich taste.

X (unacceptable): have no rich taste.

<Viscoelasticity of Beverage: Tan δ>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were produced. One daylater of the production, beverages were backed to normal temperature(25° C.) and each of the beverages was set in a viscoelasticitymeasuring apparatus (ARES100FRTN1 Type, manufactured by RheometricScientific, Inc., geometry: Double Wall Couette type, distortion wasswept in the range of 1 to 794%) to measure viscoelasticity. In thepresent invention, loss tangent tan δ (loss elastic modulus G″/storageelastic modulus G′) was obtained from the storage elastic modulus andloss elastic modulus corresponding to a distortion of 200% on thedistortion-stress curve obtained by the aforementioned measurement.

Examples, Comparative Examples: Highly Concentrated Mineral EnrichedMilk Beverage

Using cellulose composites A to K obtained in Examples and ComparativeExamples as mentioned above, highly concentrated mineral enriched milkbeverages were prepared by the following operations and evaluated. Milk(20 parts by mass), fresh cream (3.2 parts by mass) and powdered skimmilk (5.8 parts by mass) were added and stirred. To this mixture,dolomite (CaMg(CO₃)₂, density: 2.8 to 2.9 g/cm³) (0.33 parts by mass),ferric pyrophosphate (0.0067 parts by mass), zinc gluconate (0.0067parts by mass) and a cellulose composite (0.20 parts by mass) were addedand further water was added to obtain a total amount of 100 parts bymass (2 L). The resultant mixture was stirred by a high-shearhomogenizer (trade name “TK homogenizer MARKII” manufactured by PRIMIXCorporation) at 6000 rpm for 10 minutes. After stirring, a small amountof aqueous citric acid solution was added to adjust pH of the mixture tobe 6.5. After warmed up in a warm bath of 80° C., the mixture wasstirred by a propeller stirrer at 300 rpm for 10 minute and homogenizedby a piston homogenizer (trade name: “Manton-Gaulin Homogenizer”manufactured by APV) (20 MPa). This was subjected to UHT heatsterilization treatment (130° C., 3 seconds), transferred to a 200mL-volume heat-resistant glass bottle, closed tightly, and cooled withtap-water for one hour. Thereafter, the container (bottle) wasvertically gently shaken 10 times and allowed to stand still and storedin an atmosphere of 5° C. for 7 days. Appearance of the beverage wasvisually observed. The evaluation manner is as follows. The obtainedresults are shown in Table 1.

<Suspension Stability: Observation of Appearance of Food and Drink>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were visually evaluatedbased on the criteria defined with respect to the following four items.

(Sedimentation) evaluated based on the amount of deposited substance onthe bottom of a heat-resistant bottle containing beverage.

⊚ (excellent): no sedimentation, ◯ (good): partially thin sedimentation,Δ (acceptable): entirely thin sedimentation, X (unacceptable): entirelythick sedimentation

(Number of re-dispersion) a beverage contained in a heat-resistantbottle was slowly and inverted upside down, the number of inversions atthe time until no sedimentation was observed on the bottom wasdetermined as the number of re-dispersion. (example: if no sedimentationwas observed by upside down inverting once, the number of re-dispersionwas determined as one.)

<Viscosity of Beverage*The Evaluation Criteria do not Apply to FoodsExcept Beverages.>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were produced. One hourlater of the production (stored at 25° C.), each of the beverages wasset in a B-type viscometer (rotor revolving speed: 60 rpm), allowed tostand still for 30 seconds and rotated for 30 seconds, and thenviscosity was measured. Note that the rotor can be appropriately changeddepending upon the viscosity. The rotors used herein were as follows: 1to 20 mPa·s: BL type, 21 to 100 mPa·s: No. 1, 101 to 300 mPa·s: No. 2,301 mPa·s: No. 3). The measurement results were classified based on thefollowing criteria.

(Viscosity) ⊚ (excellent): 1 to 10, ◯ (good): 10 to 20, Δ (acceptable):20 to 50, X (unacceptable): 50 or more [mPa·s]

<Texture>

The evaluation criteria of texture were as follows:

⊚ (excellent): light feeling in the throat and has appropriate body.

◯ (good): slightly sticky feeling in the throat.

Δ (acceptable): heavy feeling in the throat and sticky.

X (unacceptable): good feeling in the throat but watery.

<Viscoelasticity of Beverage: Tan δ>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were produced. One daylater of the production, beverages were backed to normal temperature(25° C.) and each of the beverages was set in a viscoelasticitymeasuring apparatus (ARES100FRTN1 Type, manufactured by RheometricScientific, Inc., geometry: Double Wall Couette type, distortion wasswept in the range of 1 to 794%) to measure viscoelasticity. In thepresent invention, loss tangent tan δ (loss elastic modulus G″/storageelastic modulus G′) was obtained from the storage elastic modulus andloss elastic modulus corresponding to a distortion of 200% on thedistortion-stress curve obtained by the aforementioned measurement.

Examples, Comparative Examples: Black-Sesame Containing Milk Beverage

Using cellulose composites A to K obtained in Examples and ComparativeExamples as mentioned above, black-sesame containing milk beverages wereprepared by the following operations and evaluated. To a mixture of Oatspowder (30 g) (density 1.0 to 1.5 g/cm³), sesame paste (30 g),granulated sugar (70 g), skim milk (manufactured by Snow Brand MilkProducts Co., Ltd.) (10 g), peanut butter (manufactured by MEIDI-YA) (10g), malt extract (5 g), glyceryl monostearate (manufactured by Wako PureChemical Industries Ltd.) (1.5 g) and water (842 g), each of cellulosecomposites A to K (1.5 g) was blended and a beverage was prepared by thefollowing procedures. First, powder components mentioned above exceptwater were mixed (manually shaken for three minutes in a PE bag) andthen added the obtained mixture to water of 80° C. The mixture wasdispersed by use of a high-shear homogenizer (trade name “TKhomogenizing mixer MARKII Model 2.5” manufactured by PRIMIX Corporation,treatment conditions: rotation number 7,000 rpm×5 minutes, total amount1000 g). Subsequently, the mixture was passed once through a colloidmill (trade name “MC-1” manufactured by SMT CO., LTD.) and again heatedto 70° C. Thereafter, the mixture was homogenized by a pistonhomogenizer (trade name: “Manton-Gaulin Homogenizer” manufactured byAPV) (20 MPa), subjected to UHT sterilization treatment (140° C., 30seconds), transferred to a 250 mL-volume heat-resistant glass bottle,closed tightly, stored at 5° C. for one day and evaluated as follows.The results are shown in Table 1.

<Suspension Stability: Observation of Appearance of Food and Drink>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were visually evaluatedbased on the criteria defined with respect to the following four items.

(Separation) evaluated based on the volume of an upper thin-color layerof beverage contained in a heat-resistant bottle.

⊚ (excellent): no separation, ◯ (good): separation is less than 10%, Δ(acceptable): separation is less than 30%, X (unacceptable): separationis 30% or more

(Sedimentation) The heat-resistant bottle was slowly and upside downinverted and sedimentation was evaluated based on the amount ofdeposited substance on the bottom.

⊚ (excellent): no deposition, ◯ (good): partially thin deposition, Δ(acceptable): entirely thin deposition, X (unacceptable): entirely thickdeposition

(Aggregation) evaluated based on the amount of non-homogeneous portionin the entire beverage contained in a heat-resistant bottle.

⊚ (excellent): homogeneous, ◯ (good): slightly partiallynon-homogeneous, Δ (acceptable): partially non-homogeneous, X(unacceptable): entirely non-homogeneous

<Texture>

The evaluation criteria of texture were as follows:

⊚ (excellent): light feeling in the throat and has appropriate body.

◯ (good): slightly sticky feeling in the throat.

Δ (acceptable): heavy feeling in the throat and sticky.

X (unacceptable): good feeling in the throat but watery.

Examples, Comparative Examples: Azuki Bean-Containing Milk Beverage

Using cellulose composites A to K obtained in Examples and ComparativeExamples as mentioned above, Azuki bean-containing milk beverages wereprepared by the following operations and evaluated. To dry Azuki beans(75 g), water (1287 g) was added. The mixture was allowed to stand stillat normal temperature for 4 hours and boiled for 1.5 hours. After themixture was cooled to 70° C., it was passed once through a colloid millin the same manner as above. The treated dispersion solution was passedthrough a sieve made of SUS and having 40 meshes. After this operationwas repeated twice, a powder mixture, which was previously prepared byblending powder milk (Brite C-40, manufactured by Nestle) (15 g),granulated sugar (120 g), glyceryl monostearate (manufactured by WakoPure Chemical Industries Ltd.) (1.5 g) and a cellulose composite (1.5g), was added. The resultant mixture was treated by the aforementionedTK homogenizer at 7000 rpm for 5 minutes, homogenized by theaforementioned piston homogenizer (trade name: “Manton-GaulinHomogenizer” manufactured by APV) (20 MPa), subjected to UHTsterilization treatment (140° C., 30 seconds), transferred to a 250mL-volume heat-resistant glass bottle, closed tightly, stored at 5° C.for one day and evaluated as follows. The results are shown in Table 1.

<Suspension Stability: Observation of Appearance of Food and Drink>

Various types of beverages (as to the production method, see thefollowing Examples and Comparative Examples) were visually evaluatedbased on the criteria defined with respect to the following four items.

(Separation) evaluated based on the volume of an upper thin-color layerof beverage contained in a heat-resistant bottle.

⊚ (excellent): no separation, ◯ (good): separation is less than 10%, Δ(acceptable): separation is less than 30%, X (unacceptable): separationis 30% or more

(Sedimentation) The heat-resistant bottle was slowly and upside downinverted and sedimentation was evaluated based on the amount ofdeposited substance on the bottom.

⊚ (excellent): no deposition, ◯ (good): partially thin deposition, Δ(acceptable): entirely thin deposition, X (unacceptable): entirely thickdeposition

(Aggregation) evaluated based on the amount of non-homogeneous portionin the entire beverage contained in a heat-resistant bottle.

⊚ (excellent): homogeneous, ◯ (good): slightly partiallynon-homogeneous, Δ (acceptable): partially non-homogeneous, X(unacceptable): entirely non-homogeneous

<Texture>

The evaluation criteria of texture were as follows:

⊚ (excellent): light feeling in the throat and has appropriate body.

◯ (good): slightly sticky feeling in the throat.

Δ (acceptable): heavy feeling in the throat and sticky.

X (unacceptable): good feeling in the throat but watery.

<Color Fading after Sterilization>

Color fading was evaluated based on the following criteria.

⊚ (excellent): no color fading is observed in comparison between beforeand after sterilization.

◯ (good): color fading is slightly observed in comparison between beforeand after sterilization.

Δ (acceptable): color fading is somewhat observed in comparison betweenbefore and after sterilization.

X (unacceptable): color fading is clearly observed in comparison betweenbefore and after sterilization.

TABLE 1 Comparative Comparative Comparative Example 1 Example 2 Example3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 1 Example 2Example 3 Cellulose composite A B C D E F J K G H I Composition (mass %)Cellulose mass % 90 52 80 90 70 90 90 92 90 80 90 CMC-Na mass % 10 48 2010 5 10 10 8 10 20 10 Xanthan gum mass % — — — — 5 — — — — — — Dextrinmass % — — — — 20 — — — — — — Constitution of CMC-Na Viscosity ofComponent A mPa· s 620 7000 620 620 620 — — 500 620 — — Viscosity ofComponent B mPa · s 25 25 25 25 25 25 50 50 — 7 7 Blending ratio ofComponent A mass ratio 50 10 40 40 50 — — 25 100 — — Blending ratio ofComponent B mass ratio 50 90 60 60 50 100 100 75 — 100 100 Compositeformation Solid content mass ratio 45 45 40 50 45 45 46 48 37 11 40condition Kneading energy Wh/kg 390 220 190 100 80 200 200 250 60 30 60Kneading temperature ° C. About 40 About 40 About 60 About 65 About 65About 15 About 15 About 40 About 85 About 60 About 85 Basic physicalAverage polymerization — 220 220 220 220 220 220 220 220 220 200 220properties of composite degree of cellulose Cellulose particle L/D — 1.61.6 1.6 1.6 1.6 1.6 1.6 1.6 1.6 1.3 1.6 G′ of composite Pa 5.5 1.4 2.32.5 1.2 1.0 2.6 4 0.45 0.38 0.41 Content of colloidal mass ratio 78 6967 72 75 78 78 77 70 91 70 cellulose composite Median size by a dynamicμm 2.5 1.2 1.1 1.2 0.95 0.85 1.3 2.2 0.81 0.65 0.69 light scatteringmethod Median size by laser diffraction μm 0.13 0.13 0.13 0.13 0.16 0.130.13 0.13 0.13 0.11 0.13 Median size of coarse particles μm 6.5 9.3 8.29.1 8.5 7.8 7.5 7.8 9.5 3.4 9.3 Viscosity of water dispersion mPa · s383 252 182 220 140 175 180 330 98 80 75 of cellulose compositeEvaluation results of Separation ◯ ⊚ ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ◯ ◯ ◯ cocoa beverageSedimentation ⊚ ⊚ ◯ ⊚ ⊚ Δ ◯ ⊚ X Δ X Aggregation ◯ ⊚ ⊚ ◯ ⊚ ◯ ⊚ ⊚ ◯ Δ ◯Oil ring ⊚ ◯ ◯ ⊚ ⊚ ⊚ ⊚ ⊚ X X X Viscosity ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Texture(easy-to-drink) ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ X X X Viscoelasticity, tan δ 1.9 1.5 1.41.7 1.4 1.2 1.7 1.8 0.9 0.8 0.9 Rich taste of beverage ⊚ ⊚ ◯ ⊚ ◯ ◯ ⊚ ⊚ ΔX Δ Evaluation results of Separation ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ coffeebeverage Sedimentation ⊚ ◯ ◯ ⊚ ◯ ◯ ◯ ⊚ Δ X X Aggregation ◯ ⊚ ⊚ ⊚ ⊚ Δ ⊚ ⊚X X X Oil ring ⊚ ⊚ ◯ ⊚ ◯ ◯ ⊚ ⊚ X X X Viscosity ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚Texture (easy-to-drink) ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Viscoelasticity, tan δ 1.81.4 1.4 1.6 1.3 1.1 1.7 1.8 0.8 0.8 0.8 Rich taste of beverage ⊚ ⊚ ◯ ⊚ ◯◯ ⊚ ⊚ Δ X Δ Evaluation results of Sedimentation ◯ ◯ ◯ ◯ ◯ Δ ◯ ⊚ X X Xmilk beverage Re-dispersion times 1 2 2 1 3 3 1 0 8 10 8 Viscosity ⊚ ⊚ ⊚⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Texture (easy-to-drink) ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ X X XViscoelasticity, tan δ 1.9 1.4 1.4 1.6 1.4 1.2 1.7 1.8 0.8 0.8 0.9Evaluation results of Separation ⊚ ◯ ◯ ◯ ◯ ◯ ⊚ ⊚ X X X black sesamebeverage Sedimentation ⊚ ◯ ◯ ◯ ◯ ◯ ⊚ ⊚ X X X Aggregation ◯ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ ⊚◯ ◯ ◯ Texture (easy-to-drink) ◯ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ Evaluation resultsof Separation ⊚ ◯ ◯ ◯ ◯ ◯ ⊚ ⊚ X X X Azuki beverage Sedimentation ⊚ ◯ ◯ ◯◯ ◯ ⊚ ⊚ X X X Aggregation ◯ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ ⊚ ◯ ◯ ◯ Texture (easy-to-drink)◯ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ⊚ Color fading after sterilization ⊚ ◯ ◯ ⊚ ◯ ◯ ⊚ ⊚ ΔΔ Δ

INDUSTRIAL APPLICABILITY

Owing to addition of the cellulose composite of the present invention toa food and drink, occurrence of separation, aggregation andsedimentation of a component can be suppressed and a suspension can bestabilized. Furthermore, since the cellulose composite of the presentinvention is excellent in suspension stability, it is useful for use inrich taste beverages containing a component such as cocoa, coffee, teaand milk in a high concentration. Furthermore, the cellulose compositeof the present invention is useful since it exhibits excellentsuspension stability in foods and drinks containing a water-insolublecomponent such as a functional food material in these beverages.Furthermore, the cellulose composite of the present invention is alsouseful for medicinal products and industrial products.

The invention claimed is:
 1. A method for producing a cellulosecomposite comprising: treating a mixture containing cellulose, apolysaccharide and an aqueous medium together in a wet process, whereina solid content is controlled to be 35 mass % or more, and temperatureis set at 80° C. or less to obtain the cellulose composite comprisingcolloidal cellulose composites comprising the cellulose and thepolysaccharide and having a median size of at least 0.85 μm, the mediansize determined from: 1) suspending the cellulose composite in purewater at 0.5 mass % to obtain a suspension, 2) homogenizing thesuspension with a high-shear auto homogenizer at 15000 rpm for 5 minutesto obtain a homogenized suspension, 3) centrifuging the homogenizedsuspension in a first centrifugation at 39200 m²/s for 10 minutes toobtain a first supernatant and a first precipitate, 4) separating thefirst supernatant from the first precipitate, 5) centrifuging the firstsupernatant in a second centrifugation at 116000 m²/s for 45 minutes toobtain a second supernatant and a second precipitate, 6) separating thesecond supernatant from the second precipitate, 7) ultra-sonicating thesecond supernatant for 10 minutes to obtain a product of theultra-sonication, and 8) determining the median size of the colloidalcellulose composites from the product of the ultra-sonication by a zetapotential-particle size dynamic light scattering system, the median sizeof the colloidal cellulose composites being a cumulative 50% scatteringintensity in a frequency distribution measured by the zetapotential-particle size dynamic light scattering measurement system. 2.The method for producing the cellulose composite according to claim 1,wherein the polysaccharide is sodium carboxymethylcellulose and thesodium carboxymethylcellulose has a molecular-weight distribution, whichis obtained by gel permeation chromatography performed in a 0.05 Msodium hydroxide, having two (bimodal) peaks or more.
 3. The method forproducing the cellulose composite according to claim 1, wherein thepolysaccharide is sodium carboxymethylcellulose and the sodiumcarboxymethylcellulose contains Component A having a viscosity of 100mPa·s or more and Component B having a viscosity of less than 100 mPa·sin a mass ratio of 5/95 to 95/5.
 4. The method for producing thecellulose composite according to claim 2, wherein the sodiumcarboxymethylcellulose has a substitution degree of 1 or more.
 5. Afood, a drink, a medicinal product, or an industrial product containinga cellulose composite and a water-insoluble component in an aqueousmedium and having a loss tangent, tan δ (loss elastic modulus G″/storageelastic modulus G′) of 1.5 or more, the cellulose composite comprisingcolloidal cellulose composites comprising cellulose and polysaccharideand having a median size of at least 0.85 μm, the median size determinedfrom: 1) suspending the cellulose composite in pure water at 0.5 mass %to obtain a suspension, 2) homogenizing the suspension with a high-shearauto homogenizer at 15000 rpm for 5 minutes to obtain a homogenizedsuspension, 3) centrifuging the homogenized suspension in a firstcentrifugation at 39200 m²/s for 10 minutes to obtain a firstsupernatant and a first precipitate, 4) separating the first supernatantfrom the first precipitate, 5) centrifuging the first supernatant in asecond centrifugation at 116000 m²/s for 45 minutes to obtain a secondsupernatant and a second precipitate, 6) separating the secondsupernatant from the second precipitate, 7) ultra-sonicating the secondsupernatant for 10 minutes to obtain a product of the ultra-sonication,and 8) determining the median size of the colloidal cellulose compositesfrom the product of the ultra-sonication by a zeta potential-particlesize dynamic light scattering system, the median size of the colloidalcellulose composites being a cumulative 50% scattering intensity in afrequency distribution measured by the zeta potential-particle sizedynamic light scattering measurement system.